Log Correlation Research Articles

Centrally adjudicated vs. investigator-reported outcomes in randomized heart failure trials.

Heart failure endpoints in cardiovascular outcome trials are commonly identified through centralized adjudication of investigator-reported events. It remains unclear whether central adjudication improves the accuracy of treatment effect estimates in terms of log[hazard ratios (HR)]. Data from seven cardiovascular outcome trials with >1000 patients that included centrally adjudicated heart failure outcomes were utilized to assess (i) the concordance between investigator-reported and centrally adjudicated heart failure and cardiovascular death events; (ii) rates of subsequent all-cause mortality following positively vs. negatively adjudicated heart failure events; and (iii) the correlation of log(HR) based on centrally adjudicated vs. investigator-reported events. Positive adjudication rates for investigator-reported events varied widely across trials, but were generally higher for cardiovascular death (range: 87.9%-99.2%) than for heart failure hospitalization (range: 61.6%-88.0%). The risk for subsequent all-cause death was similar for positively and negatively adjudicated heart failure hospitalizations. Log(HR) correlated well for cardiovascular death [R2 = .80, 95% credible interval (CrI): 0.53-0.93] and the composite of cardiovascular death or heart failure hospitalization (R2 = .79, 95% CrI: 0.46-0.93), but less for heart failure hospitalization (R2 = .57, 95% CrI: 0.10-0.83). Positive adjudication rates were lower for heart failure events than cardiovascular death, but even negatively adjudicated heart failure events are prognostically important. Central adjudication of events did not alter the results (precision or estimated log(HR)), though some variation was observed, depending on the indication. The results suggest that the decision to pursue centralized adjudication of heart failure events in a specific trial may need to be individualized.

The Lockman-SpReSO project

Aims. In this work, we carry out a comprehensive study using galaxy data from the Lockman Spectroscopic Redshift Survey using Osiris (Lockman-SpReSO) project, a far-infrared (FIR) selected sample of galaxies observed using optical spectroscopy. We analyse a sub-sample of star-forming galaxies (SFGs) with secure spectroscopic redshifts, mostly in the luminous infrared (IR) galaxy domain. From these galaxies, parameters such as the extinction, star formation rate (SFR), and metallicity have been derived. The present paper examines how these properties evolve in relation to each other and in comparison with low-redshift FIR and non-FIR-selected samples of galaxies. Methods. We applied distinct selection criteria to attain an SFG sample with minimal AGN contamination. Multiple approaches were used to estimate the intrinsic extinction, SFR, and gas-phase metallicity for the SFGs. In conjunction with findings in the literature, we examined the correlation between SFRs and stellar masses (M*), as well as the metallicity evolution depending on M*. Finally, we also studied the 3D relationship between M*, SFR, and metallicity. Results. From the initial spectroscopic sample of 409 FIR-selected objects from the Lockman-SpReSO catalogue, 69 active galactic nuclei (AGNs) were identified and excluded (17%), which is nearly double the percentage found in local studies, leaving us with a sample of 340 SFGs. The analysis of the M*–SFR relationship revealed that Lockman-SpReSO IR-selected SFGs show signs of evolution at redshifts z > 0.4, shifting above the main sequence (MS), with a mean value of ∼0.4 dex. They are located within the starburst galaxy region since 78% of the galaxies fall into this category. In addition, no evident flattening was found in the relation to specific SFR with redshift for log M* (M⊙)≳10.5. In line with the M*–metallicity relation (MZR) outcomes published in previous studies for optically selected SFGs; however, during the analysis of the MZR, it was found that IR-selected SFGs exhibit lower metallicities than the values anticipated on the basis of their M* and redshift. During the investigation of the 3D M*–SFR–metallicity relation (FP), it was established that the research sample is consistent with relations published in the existing literature, with an average scatter of ∼0.2 dex. However, a re-calibration of the FP when using the SFR obtained from the IR luminosity is required and, in this case, no attenuation in the correlation for log M* (M⊙)≳10.5 was observed. This result points to a possible evolution of the more massive fraction of the sample in the sense that the present-day star formation rate is lower with respect to the average rate of star formation in the past.

T-Trace: Constructing the APTs Provenance Graphs Through Multiple Syslogs Correlation

Advanced Persistent Threats (APTs) employ sophisticated and covert tactics to infiltrate target systems, leading to increased vulnerability and an elevated risk of exposure. Consequently, it is essential for us to proactively create an extensive and clearly outlined attack chain for APTs in order to effectively combat these threats. Unlike traditional malware or application threats, APTs can sidestep cyber security efforts and cause severe damage to organizations or even state security. Nonetheless, earlier methods struggle to accurately track APTs and may face a dependency explosion issue, as identifying the intricate and complex unknown malicious activities within APTs proves to be challenging. In this paper, we propose and build an approach, T-trace, which constructs the events provenance graphs by analyzing the correlations among logs. The approach precisely finds the log communities with tensor decomposition and calculates significance scores to extract the events. The APTs can be inferred by discovering the event communities and constructing the provenance graph with log correlation. In the experiment, we used DARPA data sets and launched four current practical APTs. Compared with current approaches, the results show that T-trace can efficiently reduce time cost by 90% and achieve a 92% accuracy rate in constructing the provenance graph, which can be practically applied in APTs provenance.

Stratigraphic and Petrophysical assessment of ASL sandstone reservoir in northern and central October Field, Gulf of Suez

ABSTRACT This study analysed the depositional environment and diagenesis of the ASL Member reservoir in the October oil field located in the Gulfof Suez Basin, Egypt. Sedimentological and petrophysical techniques were used to interpret data from four wells: OCT-J7B, GS173-2, GS184-4A, and GS195-3, penetrating various rock types, including sandstone, carbonate, and fractured basement reservoirs. Log correlations of OCT-J7B and GS173-2 showed they penetrated pre-Miocene strata, while GS184-4A and GS195-3 reached the Rudeis section. Based on seismic-based structural maps, all wells except GS173-2 were drilled down-dip of the main Clysmic fault. The Hawara shale and the older shales in the Rudeis section were found to be the reservoir’s lateral seal, and the Lagia shale was found to be its vertical seal. Core analysis of OCT-J7B revealed the ASL as limestone interbedded with shale and sandstone deposited in a proximal submarine fan lobe, while GS184-4A and GS195-3 were located in amid-fan carbonate system. The comparisons of core and log data from the four wells yielded excellent matches, and the iso-parametric mapping delineated reservoir quality horizontally and hydrocarbon potentiality. The study recommends sitting future wells away from uplifts and suggests further reservoir characterization and evaluation of potential zones in the ASL Member.

Structural and Stratigraphic Reservoir Characterization of “MONI” Field¸ Niger Delta.

Reservoir characterization of “MONI” field of the Niger Delta has been carried out using well log and seismic data. The study is aimed at delineating structural and stratigraphic features associated with hydrocarbon entrapment of the field. Lithostratigraphic correlation reviewed two main lithologies which are reservoir sands and seal shales. Well log correlation and interpretation across the field indicates – main stratigraphic bounding surface which include two sequence boundaries and one maximum flooding surface. This indicates about three depositional sequences exists in the study area. Stacking patterns (progradation, retrogradation, and aggradation) were delineated and interpreted as lowstand system tract (LST), highst and system tract (HST), and transgressive system tract (TST). The alternation of LST, HST and TST offers good reservoir and seal for the hydrocarbon accumulation. The depositional environment of the reservoirs ranges from subaerial channel deposits, barrier bar, tidal channel sands to delta distributary channel fill. Subaerial channel deposits have a bad reservoir quality, tidal channel sands possess a fair reservoir quality while delta distributary channel fill have a good reservoir quality. Petrophysical analysis shows that three reservoirs delineated have a porosity ranging from 19.37% to 23.62%, permeability ranging from 1408.71 to 1855.36 mD, a Net-to-Gross ranging from 0.46 to 0.88, volume of shale ranging from 11.72% to 24.92%, Water saturation ranging from 37.24% to 47.96% and hydrocarbon saturation ranging from 52.04% to 62.76%. Structural interpretation reviewed four main faults that serves as traps to the accumulation of hydrocarbon. Three hydrocarbon bearing sands were interpreted in the seismic volume. Time and depth structure maps show that the hydrocarbon bearing structure is a fault assisted anticlinal structure. Seismic facies analysis reviewed five facies. The study concluded that structural and stratigraphic features can be used to characterize reservoirs.

Cross-border correlations showing diachronous lithostratigraphic units in the southeastern North Sea Basin during the Early Oligocene (middle-late Rupelian)

Abstract Wireline log correlation panels of palynologically analysed boreholes illustrate lateral facies transitions within Rupelian age strata of the Dutch Rupel Formation across the southeastern North Sea Basin. The middle to upper part of the Rupel Formation consists of clays and silts of the Boom Member and the overlying sandier Steensel Member. In the Mill and Goirle boreholes in the Dutch Province of North Brabant, the Boom Member is thickly developed and represents the middle to upper Rupelian (biozones NSO3 to NSO5a), while the Steensel Member is rather thinly developed and only comprises the uppermost Rupelian (biozone NSO5a). Borehole log correlations show that towards the south (or more proximal to the palaeo-continent) the Rupel Formation becomes sandier and the clayey Boom Member thins in favour of the sandy superjacent Steensel Member. Palynological analyses confirm that the Boom Member is restricted to the middle Rupelian (biozone NSO3) age here, and that the superjacent Steensel Member is of middle to upper Rupelian age (biozones NSO3 to NSO5a). Geological models constructed for northern Belgium propose that this facies transition occurs rather sharply, along a WSW-ENE oriented zone parallel to the presumed shoreline at that time. The results of this study support this interpretation and extend the trend towards the Netherlands.

Factors affecting diffusion of polar organic compounds in agarose hydrogel applied to control mass transfer in passive samplers.

Diffusive hydrogel-based passive sampler (HPS) based on diffusive gradients in thin films (DGT) is designed for monitoring polar organic contaminants in the aquatic environment. DGT technique controls the compound's overall uptake rate by adding a hydrogel layer of known thickness, which minimizes the importance of the resistive water boundary layer in the compound uptake process. In this work, we investigated several factors which may influence the diffusion of a range of aquatic contaminants in 1.5% agarose hydrogel. Diffusion in hydrogel was tested using the sheet stacking method. We demonstrated that a thin nylon netting incorporated into the diffusive hydrogel for mechanical strengthening does not significantly affect the diffusion of 11 perfluoroalkyl compounds. Further, we investigated the effect of pH in the range from 3 to 11 on the diffusion of a range of 39 aromatic amines (AAs)-36 aromatic, 2 aliphatic, and azobenzene in hydrogel. AAs were chosen as representatives of compounds with pH-dependent dissociation in water. Analysis of variance showed no significant difference in meandiffusion coefficient log D value at five pH values. The demonstration that the diffusion coefficient D and thus the sampling rate Rs are independent on pH simplifies the interpretation of data from field studies because we can neglect the influence of pH on the Rs. log D values (m2 s-1) of tested AAs ranged from to - 9.77 for 3,3'-dimethylbenzidine to - 9.19 for azobenzene. A negative correlation of log D with molar mass (log M) and molecular volume (log Vm) was observed (R = - 0.57 and - 0.56, respectively). The diffusion coefficient presents a critical parameter for the sampling rate estimation of HPS. Theoretical sampling rates Rs of AAs were calculated for a HPS using the average D values. TheoreticalRs values calculated for AAs at 22°C ranged from 29 mL day-1 for 3,3'-dimethylbenzidine to 106 mL day-1 for 2-aminopyridine. Our calculated values of Rs are in the same range as those already published for a range of low-molecular polar organic contaminants, which supports the possibility of deriving sampler performance parameters in the field from laboratory-derived diffusivity of analytes in hydrogel.

The Charnwood Terrane revisited: an integrated petrogenetic and petrophysical model for crustal structure in southern Britain

We based an integrated petrological and petrophysical model for the Ediacaran crust of southern Britain on a review of the c. 570–550 Ma Charnian volcano-sedimentary complex. The latter was emplaced in a magmatic rift wedge within the juvenile continental crust of the c. 720–600 Ma Marches Terrane, a subduction magmatic domain formed at the margin of the Gondwana palaeocontinent. The Charnian magmatic arc is characterized by primitive island arc tholeiite to more evolved calc-alkaline compositions. The inversion of aeromagnetic potential field data and petrophysical modelling reveals details of the internal structure of the Charnian Domain, including a median rift, superimposed annular structures and partitioning lineaments. The modelling suggests that the arc foundation could incorporate magnetite-rich cumulates, which may explain the anomalous geophysical properties, including crustal thickness, rigidity and buoyancy. There is no evidence for significant tectonic displacement between the Charnian Domain and its Marches Terrane host. Instead, the domain likely occupies a wedge-shaped arc/marginal rift basin complex, propagated from a neighbouring ocean into the Gondwana margin. Contemporaneous volcanic rift successions in the Welsh Borderland and Wales of the 570–550 Ma Charnian magmatic phase developed in coeval ensialic rifts within less strongly extended Marches Terrane lithosphere. A comparable diversity of subduction-related magmatism is found in the Neogene–recent Hikurangi destructive margin of New Zealand, providing a plausible analogue for Charnian magmatism. Supplementary material: Supplementary Publication 1 (borehole geophysical log correlation; petrophysical data table; unannotated geophysical maps and sections) and Supplementary Publication 2 (geochemistry analytical conditions and data table) are available at https://doi.org/10.6084/m9.figshare.c.6805248

Linking anoxia, biotic events, and basin evolution in the Late Devonian Illinois Basin, North America: A geochemical approach

Epeiric seas and their sedimentary deposits are vital for understanding the history of Earth's oceans, but the lack of modern analogues and the frequent dominance of uniform mudrocks in these environments hinder our ability to identify key markers and interpret sea-level changes and past climatic/biotic events in epeiric sea successions. This study focuses on the Late Devonian Illinois Basin, where fine-grained mudrocks, occasionally organic-rich, were deposited in one of many variably interconnected epeiric seas that flooded much of the North American craton. Through the correlation of gamma logs from 50 wells across the basin and the generation of high-resolution chemostratigraphic profiles for four cores, a basin evolution model for the Upper Devonian New Albany Shale (NAS) in the southeastern depocenter of the Illinois Basin (USA) is established. Results indicate that NAS deposition occurred in three phases, characterized as one aggradational-progradational, one progradational, and one retrogradational package. The basin experienced an initial flooding event at the base of the NAS, followed by a second transgression immediately after the Frasnian-Famennian boundary (FFB). The mid- to upper Famennian interval witnessed progressive sea-level rise (a third transgression) and full basin inundation, extending nearly to the top of the NAS. Based on redox proxy data, four discrete anoxic pulses were identified during NAS deposition. By incorporating published biostratigraphic and geochemical datasets, we then correlate these signals observed in the Illinois Basin across the Appalachian, Michigan, Permian, and Anadarko basins of the broader North American Seaway. Additionally, some of the anoxic pulses are linked to key biotic crises of the Late Devonian, such as the Rhinestreet, Upper Kellwasser, and Enkeberg events, which caused substantial turnover in the marine biosphere. This study contributes an integrated basin evolution framework for the Late Devonian North American Seaway and serves as an exemplar of utilizing geochemical signals to correlate sea-level changes, anoxic pulses, and key biotic events in ancient mud-dominated epeiric seas.

Structural and petrophysical characteristics of the Turonian “AR/G″ reservoirs in heba field (Western Desert, Egypt): Integrated approach for hydrocarbon exploration and development

The evaluation of the Turonian “AR/G″ reservoirs in the Heba field, located in the eastern part of the Abu Gharadig Basin in the Western Desert of Egypt, is a crucial aspect of hydrocarbon exploration and development in the region. To achieve this, a comprehensive analysis of wells and seismic data was conducted. The seismic interpretation revealed that the Upper Cretaceous dextral wrenching tectonic has influenced the Heba field and extends throughout the northern Western Desert. Through the integration of seismic attributes, such as RMS and Sweetness, and well log correlation during the mapping phase, an ENE-WSW faulted anticline structure was identified in the study area. This geological feature was found to be plunging towards the NW direction and stretches throughout the study area, although it is fragmented by several NW-SE and WNW-ESE normal faults with lengths ranging from 1 to 10 km. The well log analysis of the AR/G Member has identified two proposed oil zones (Zone 1 and Zone 2), both exhibiting good reservoir quality across all examined wells. These oil zones are characterized by low to moderate shale volume (15%–40%), high total porosity (20%–28%), moderate effective porosity (15%–17%), moderate water saturation (40%–67%), and low bulk volume of water (6%–9%). These findings suggest that the AR/G Member has the potential to be a productive hydrocarbon reservoir. Integrating the structural and petrophysical characteristics of the “AR/G″ reservoirs can greatly assist in identifying suitable locations for oil exploration and development in the study area. This integrated approach enhances the ability to predict the behavior and production potential of the “AR/G″ reservoirs in the Heba field (Western Desert, Egypt).

Integration of Geological, Geochemical Modelling and Hydrodynamic Condition for Understanding the Geometry and Flow Pattern of the Aquifer System, Southern Nyírség–Hajdúság, Hungary

Geological heterogeneity impacts groundwater flow patterns, necessitating a detailed hydrogeological framework for conceptualization process of aquifer systems. This research developed a new conceptual model of detailed geologic geometry by integrating 133 well-logs, 366 hydrodynamic data and 118 water samples. As new results, systematic 3D log correlation detected four distinct hydrostratigraphic units in the Southern Nyírség–Hajdúság Groundwater Body (East Hungary). The primary aquifer was identified as an incised valley 10–13 km wide and a NE–SW strike. Logan’s approach estimated the average hydraulic conductivity of the Incised Valley Unit (IVU) at 11 m/d, higher than the other three aquifers (3.2 m/d to 4.6 m/d). The average specific capacity of wells screening the IVU is 315.6 m3/d/m, in contrast with the remaining aquifers ranging from 31.6 m3/d/m to 92 m3/d/m. Pressure–depth profiles, dynamic pressure increment and hydraulic head maps revealed recharge–discharge zones and hydraulic windows between hydrostratigraphic units. The elongated pattern on the hydraulic head map at the depth of the IVU showed the existence of a preferential path along its axis within the mapped borders of the IVU. Hydrochemical analysis revealed Ca-Mg-HCO3 water type within the primary aquifer and Na-HCO3 water type in the laterally connected aquifer. The saturation index values indicated a transition from undersaturated to supersaturated state inside the main aquifer for calcite and dolomite minerals. The correlation matrix and PCA results demonstrated that the carbonate weathering process is the main factor controlling the groundwater chemistry. This integrated approach holds significance for future applications of the regional conceptual model in water management planning, sustainable aquifer development and contaminant transport modelling. It provides essential contributions to informed decision-making and the formulation of effective strategies, ensuring the long-term availability and utilization of groundwater resources.

Optimization of Security Information and Event Management (SIEM) Infrastructures, and Events Correlation / Regression Analysis for Optimal Cyber Security Posture

This work integrates logical and physical security processes, and simplifies the manageability of the security infrastructure. The process increases visibility to resources, which makes it easier to prevent security incidents, and provides a platform to manage the response and recovery after an incident occur. Log collection is the heart and soul of a SIEM. Log correlation is employed to identify particular sequences of log events from devices. The comparison between network level and host level events automatically perform initial validation that would not normally be performed. It considers movement of data between systems where it would not normally accounts logging on at unusual times or from unusual places, these may not generate specific security alerts, but can be much more easily spotted and flagged by a log correlation solution that sees everything in the environment. It shows some enhancements to event log normalization and significantly improves correlation rule execution. The event monitoring algorithm and SIEM correlation rules result in false positives or false negatives. Security managers, therefore, may waste time and resources that could be used to respond to real threats and assaults if there are too many false positives. This study hereby, strikes a compromise between lowering false positive alerts and not ignoring any potential abnormalities that could indicate a cyberattack when establishing SIEM correlation rules. In order to decide which data is pertinent and which data is irrelevant in an event pipeline, this research employs the use of filters. Through this examination, it can be inferred that the conditions are advantageous for promoting investment in the growth and enhancement of this technology as an essential component of industrial control systems with security operation centers, as well as offering cyber security management for small and medium-sized enterprises (SMEs) with restricted security expertise and capabilities.

Depositional facies analysis of coastal to shallow marine deposits in the onshore Niger Delta Basin: Accessing the influence of sedimentology and depositional environments on reservoir quality

Sedimentology and depositional environment of E2000-Sand in the southern part of the Central Swamp depobelt have been studied using core and wireline log data. Nine wells were used for the study, one of which has some 200ft of core in the southern part of the field. Key wells were correlated based on normalized gamma-ray and other logs. Using two main panels, one along the depositional dip across syn-sedimentary intra-field faults and another along strike, lateral continuity, reservoir development, and shoreline proximity were evaluated. The cores were described to identify lithology, sedimentary structures, depositional processes, and genetic units. The results from the electro-facies analysis, wireline log correlation, core description, and core permeameter measurements were integrated to interpret depositional environments. The E2000-Sand normalized gamma-ray log profile showed three broad sections made up of (from bottom to top) a coarsening upward funnel-shaped basal section overlain by an overall cylindrical-shaped gamma-ray log signature capped by a short coarsening upward funnel-shaped interval. The overall gamma-ray log profile is consistent with a deltaic progradational setting typical of a shoreface sequence inundated by channel activities. Seven genetic units were identified in the cored interval comprising Marine Shale, Offshore Transition Heteroliths, Lower Shoreface, Upper Shoreface, Lagoonal Shale/ Heterolithics, Tidally Influenced Channel/Crevasse Splay, and Distributary Channel. Petrophysical analysis of these units showed a direct correlation between lithofacies type and grain size with flow properties deteriorating with decreasing grain size. Using such attributes as permeability, porosity, and grain size, four genetic units in the sand namely Lower Shoreface, Upper Shoreface, Tidal Channel, and Distributary Channel were interpreted as reservoir units. The best reservoir flow properties were preserved in the Distributary Channels with a porosity range of 20-29%, permeability in the range of 3,300-9,900mD and average grain size ranging from 177-500μ, while the Lower Shoreface corresponded to the worst quality reservoir units with porosity ranging from 17-26%, permeability varying from 0.01-180mD, and average grain size varying from 62-125μ. Three of the genetic units including Offshore Transition Heteroliths, Lagoonal Shales/Heterolithics, and Marine Shale were interpreted as non-reservoir units with porosity and permeability ranging from 4-17%, and 0.03-36mD respectively, while average grain size was below resolution. The E2000-Sand is interpreted as deposited in a coastal shoreface/delta mouth shallow marine setting. Reservoir quality in the sand is strongly faciesdependent with sedimentology and depositional environments controlling the reservoir properties of the sand bodies.

Obliquity‐driven mountain permafrost‐related fluvial magnetic susceptibility cycles in the Quaternary mid‐latitude long‐term (2.5 Ma) fluvial Maros Fan in the Pannonian Basin

Magnetic susceptibility (MS) of the Quaternary long‐term mid‐latitude Maros fluvial fan (Pannonian Basin) was recorded to understand the stratigraphical features of source‐proximal fluvial depositional settings. Three fully cored 500‐m‐deep boreholes were sampled at 0.5‐m intervals; low‐field and frequency dependent MS were measured, and complementary hysteresis and SEM‐EDAX investigations were performed on selected samples. Logged susceptibility data were also used to log correlations established by a simultaneous comparison of wireline log and laboratory measurements. Time‐series analyses of the susceptibility records reveal a ~41‐ka and ~100‐ka cyclicity. Towards the source‐distal sections the intensity of the ~41‐ka cycles decreases, while that of the ~100‐ka cycles remains strong. Stratigraphical and spectral similarities were observed between the Maros fluvial fan and Chinese loess records; however, based on complementary magnetic data, the magnetic phase of the Maros Fan sections is related to the detrital magnetite that originates from the catchment during early postglacial permafrost degradations. The amplification of the ~41‐ka cycles can be attributed to the very high susceptibility values in source‐proximal settings and to the special stratigraphical feature of the distributive fluvial systems. This comprises the increased avulsion frequency on the fluvial fans in ‘glacial recession periods’, in concert with the ‘early postglacial’ occurrence of the permafrost‐related magnetite originating from the catchment. As a local phenomenon, this is significant since it records the obliquity‐driven variations in permafrost development in a catchment. However, fluvial and alluvial fans are widespread depositional landforms within the Eurasian mountain range and were possibly the same during the Quaternary deglaciations. Thus, obliquity‐driven magnetic susceptibility variations in source‐proximal fan deposits attached or adjacent to regions of loess deposition should also be considered when scanning for potential source material of aeolian deposits.

A new objective function designed for the calibration of stratigraphic forward models

This paper presents a novel and quantitative method of comparing facies successions of distinct sizes and resolutions, adapted for the automated calibration of stratigraphic forward models (SFM). The method, which corresponds to the calculation of an objective function, consists of correlating time-sampled SFM results with space-sampled well logs using a strategy inspired by methods of automated well log correlation. The method was designed to be generic and to accept multi-variate definition of facies, so that it can be applied in a variety of geological contexts (e.g., mixed carbonate-clastic environments). The method demonstrated properties suitable for automated calibration, such as a smooth and almost convex relationship with individual simulation parameters. The method was applied to a case-study using gradient-based, meta-heuristic, Bayesian, and random optimization strategies in an 8-dimensional uncertain space. The results show that calibrated models can be found, but there are still non-uniqueness issues due to compensation effects between uncertain parameters. Therefore, a calibration strategy capable of identifying these multiple solutions is necessary to propagate geological uncertainties in petroleum system assessments and field production predictions.

Direct Assessment of Oligomerization of Chemically Modified Peptides and Proteins in Formulations using DLS and DOSY-NMR.

Protein higher order structure (HOS) including the oligomer distribution can be critical for efficacy, safety and stability of drug products (DP). Oligomerization is particularly relevant to chemically modified protein therapeutics that have an extended pharmacokinetics profile. Therefore, the direct assessment of protein oligomerization in drug formulation is desired for quality assurance and control. Here, two non-invasive methods, dynamic light scattering (DLS) and diffusion ordered spectroscopy (DOSY) NMR, were applied to measure translational diffusion coefficients (Ddls and Dnmr) of proteins in formulated drug products. The hydrodynamic molecular weights (MWhd), similar to hydrodynamic size, of protein therapeutics were derived based on a log(Ddls) vs log(MWhd) correlation model established using protein standards. An exponent value of -0.40 ± 0.01 was established for DLS measured log(D) vs. log(MWhd) using protein standards and a theoretical exponent value of -0.6 was used for unstructured polyethylene glycol (PEG) chains. The analysis of DLS derived MWhd of the primary species showed the fatty acid linked glucagon-like peptide 1 (GLP-1) was in different oligomer states, but the fatty acid linked insulin and PEG linked proteins were in monomer states. Nevertheless, equilibrium and exchange between oligomers in formulations were universal and clearly evidenced from DOSY-NMR for all drugs except peginterferon alfa-2a. The correlation models of log(D) vs. log(MWhd) could be a quick and efficient way to predict MWhd of protein, which directly informs on the state of protein folding and oligomerization in formulation.

Structural and Mineralogical Characterization of the Clayey Deposits of Gbédji-Kotovi in Lama Depression, Bénin

The objective of the study was to characterize the clays of the Lama depression in Benin. Macroscopic examination of hand soundings, dynamic penetration test and stratigraphic correlation of water borehole logs, as well as scanning electron microscopy (SEM) combined with energy-dispersive X-ray microanalysis (EDX) method were made on compact or stratified clays. The large grains are embedded in a sintered matrix. The texture is heterogeneous and open, including quartz, carbonates and organic matter. The fine fraction is dominated by mineral paragenesis characterizing Kaolinite-Quartz-Calcite-Gypsum dioctahedral smectites composed of: Oxygen, Silica, Carbon, Aluminum, Iron, Zinc, Titanium and Magnesium. This smectic and regular structure includes coarse grains of the order of 800 μm. The pore diameters vary from 130 μm to 1.14 μm. The inter-particle porosity is poorly developed unlike the inter-aggregate pores larger than 0.05 μm. The texture is laminar and shows elongated turbo static particles with more or less rounded edges and honeycomb particles. Quartz and carbonates induce an increase in heterogeneities which develop mechanical sensitivity and hydraulic conductivity. High contents of silica, iron or aluminum and low contents of calcium and magnesium, as well as the presence of other trace elements suggest an alumino-ferriferous clay resulting from the hydrothermal alteration of the acid granite massif. These heterogeneities promote less tortuous pores or paths, making these clays more permeable. Finally, other stabilization studies and improvements to hydraulic products and binders should favor the use of the studied clay as improved backfill or drilling muds.

RESERVOIR CHARACTERIZATION OF THE ‘SHULA FIELD’, OFFSHORE NIGER DELTA BASIN, NIGERIA: AN INTEGRATED APPROACH

This study analyzed “Shula field” offshore Niger Delta basin for it hydrocarbon bearing capacity. Well logs and seismic data were used for the analysis. Well logs consisting of gamma ray, resistivity, neutron and density logs for five different wells were used. Gamma ray logs aided lithological identification, resistivity logs were used to delineate hydrocarbon bearing zones while a combination of neutron and density logs aided in distinguishing oil and gas zones. Three hydrocarbon bearing sands (reservoirs) of varying thickness designated as RES-AA, RES-BB and RES-CC were identified. Well log correlation of the five wells revealed lateral continuity of the sand units thinning out in northwestern direction of the study field. The range values of gross thickness (GT), net-to-gross (NTG), volume of shale (VSH), effective porosity (ΦEff), permeability (K), hydrocarbon saturation (Sh) and water saturation (SW) for RES-AA reservoir are 51-74ft, 0.88-98%, 0.10-11%, 24-28%, 174-734mD, 8-80%, and 20-92% respectively. RES-BB reservoir range values of (GT), (NTG), (VSH), (ΦEff), (K), (Sh) and (SW) are 47-65ft, 83-98%, 8-14%, 24-32%, 234-1880mD, 4-78%, and 22-96% respectively while the RES-CC reservoir range values of (GT), (NTG), (VSH), (ΦEff), (K), (Sh) and (SW) are 121-191ft, 82-96%, 8-11%, 23-31%, 125-1352mD, 9-88% and 12-91% respectively. Sixteen faults were identified and interpreted comprising of nine synthetic and seven antithetic faults. The time and depth structural maps show the subsurface structural geometry and possible hydrocarbon migration and trapping potential. The probable structure trapping hydrocarbon in the study field is anticlinal structure and four-way closure. The volumetric calculation revealed that reservoir RES-AA has 951 × 106 bbl, reservoir RES-BB has 1058 × 106 bbl and reservoir RES-CC has 1688 × 106 bbl of oil originally in place (OIIP). Generally, the petrophysical results and the volumetric calculation for the field confirm an economically viable investment potential except for reservoir RES-AA, wellbore ZY-005 with 8% Sh, reservoir RES-BB, wellbore ZY-003 and ZY-005 with 4% Sh, and 7% Sh respectively and reservoir RES-CC, wellbore ZY-005 with 9% Sh. Therefore, these four reservoir units may be screen out during production to reduce the rate of water cut thereby increasing the producing life of the field.

An end-to-end method for advanced persistent threats reconstruction in large-scale networks based on alert and log correlation

Nowadays, advanced persistent threats (APTs) compromise critical large-scale networks more frequently, however, detecting these APTs is difficult. Since security sensors often miss some key steps of APTs, a lot of missed alerts exist. Moreover, large-scale networks often generate thousands of repeated alerts every day. To address this issue, a novel method for APT reconstruction in large-scale networks is proposed for attack forensics and traceability in this paper. Additionally, the proposed method consumes low transmission cost, and it doesn't require raw data from terminal devices, which makes it more appropriate for large-scale networks with numerous terminal devices. Specifically, an alert reduction and correlation method is first designed to reduce the alert volume. Then, these alerts are transformed into an alert graph, and the key missed alerts are obtained by searching history alerts and logs using Monte Carlo Tree Search (MCTS), which fast assembles multi-stage attacks with high confidence. The evaluation results on the modified CSE-CIC-IDS-2018 dataset indicate that the proposed method is robust against false negatives. Compared with other research, the proposed method has more advantages in efficiency and accuracy, and it can detect APTs within a longer time horizon.

Reactivity of nitrogen species with inorganic and organic compounds in water.

Many studies on the reactive nitrogen species (RNS, ●NO2, ●NO and ●NH2) with pollutants in water have been performed to understand the abatement of inorganic and organic compounds by these species, and the mechanisms of the formation of oxidative transformation products, especially nitrogenous oxidized byproducts. In this review, approaches to generate RNS in aqueous solution is first presented, followed by a summary of their reactivity with a wide range of compounds. The second-order rate constants (k, M-1 s-1) for the reactivity of ●NO2 and ●NO with a wide range of inorganic radical and nonradical species were correlated with thermodynamic one-electron oxidation potentials (E0). The positive correlation between log(k) versus E0 suggests one-electron transfer reactions. The Hammett-type correlations were developed for the reactions of ●NO2 and ●NH2 with organic compounds, using the unsubstituted benzene as a reference molecule (i.e., Σσo,p,m=0) to calculate Σσo,p,m=σo+σp+σm for each organic molecule. Linear negative correlations of log(k) with Σσo,p,m were obtained for both ●NO2 and ●NH2, suggesting electrophilic substitution mechanism. The correlations presented herein may assist in eliminating organic micropollutants in water treatment and reuse processes.