Major Units Research Articles

Multi-objective optimization of a fluid catalytic cracking unit using response surface methodology

Abstract In oil refineries, fluid catalytic cracking (FCC) is a major unit consisting of several process variables and multiple products. Since FCC units are given prime importance as they are contributing a large share in profits, the optimal operation of FCC is always desirable while considering the changing economic scenarios with respect to the products. However, optimization of FCC is quite challenging due to the complex nature of the process. In this work, using Aspen HYSYS V9® catcracker module, process data of FCC was obtained using central composite design (CCD). Second order regression equations for the selected responses were obtained using Analysis of variance (ANOVA) approach. The interaction effects of feed flow, feed temperature, feed pressure, air blower discharge temperature and catalyst circulation rate on responses (yield of products) were presented. Further, the optimization was performed based on a multi-response optimization technique in the Design expert software and the optimal values of the input variables were obtained for the chosen objectives (representing various operation scenarios). The optimal operation scenarios that were obtained for the objectives were validated successfully. This work highlights the use of statistics based soft computing techniques for the optimization of complex chemical engineering operations such as FCC.

Isotopic, Geophysical, and Hydrogeochemical Investigations of Groundwater in West Middle Upper Egypt.

The groundwater of the west Assiut and El-Minia districts was evaluated in this paper using geoelectrical, hydrogeochemical, and stable isotope (oxygen-18 and deuterium) studies. In the studied localities, 42 vertical electrical soundings (VES) were taken to evaluate groundwater potential, and the analysis, as well as collection, of 74 samples of Eocene groundwater was carried out. In accordance with the vertical electrical soundings' interpretation, there are four geoelectrical formations and two major water-bearing units that act as aquifers (Pleistocene and Eocene). To determine irrigation suitability, the sodium absorption ratio (SAR), electrical conductivity (EC), residual sodium carbonate (RSC), sodium percentage (Na %), magnesium hazard (MH), Kelley's ratio (KR), and permeability index (PI) were evaluated as irrigation quality parameters. The EC, Na %, and the diagram of the US salinity laboratory indicated that most of the collected samples of groundwater were suitable for irrigation, whereas the RSC and PI pointed out that all of the collected water samples were safe for irrigation. The oxygen and hydrogen isotope values in groundwater samples showed that the Eocene aquifer was recharged by both surface water and the Nubian aquifer.

Environmental quality-oriented air pollution emission permit allocation methods: A plant-level study

When implementing the emission permit system to control air pollution, current research mainly adopts top-down approaches to allocate emission quotas, lacking practicability at the plant level. In this study, two new plant-level permit allocation methods are proposed in consideration of the interference of environmental factors to help allocate emission quotas more effectively. These methods adjust the commonly-used emission standard permit allocation method by introducing the transmission of air pollutants between sources and receptor cities or by introducing the constraint of the environmental capacity. The study is conducted based on plant-level production data from 11,398 major emission units in the seven core cities of the Beijing-Tianjin-Hebei region, China. In 2017, these units emitted 139.7 thousand tons of primary PM2.5, 223.2 thousand tons of SO2, and 281.5 thousand tons of NOX, accounting for 24.8%–58.6% of the regional total emissions. The new methods could reduce emissions by up to 82.4% and reduce pollution concentrations by 12.3% maximumly. The slopes of the linear regressions between the issued and the allocated plant-level permit quotas are between 0.60 and 0.97, indicating the new methods perform well in reducing emissions at the plant level. However, as emission reduction is the ultimate outcome of multiple factors, these methods sometimes still cannot control pollution concentrations below the air quality standards due to the relatively loose environmental policy. Thus, it is recommended to tighten the emission standards to further reduce allocated permits. Overall, this work provides significant insight into improving emission allocation policies using plant-level data in real-world environmental governance in China.

Attempted Suicide by Burning: A Cross-sectional Analysis at a Regional Burn Center in Germany.

Attempted suicide by self-immolation or burning constitutes an uncommon form of attempted suicide in high income countries, presenting substantial challenges to burn units. The aim of this study was to analyze the epidemiologic characteristics and outcomes in intensive care burn patients treated for attempted suicide by burning. For this purpose, we examined intensive care burn patients admitted to a single major burn unit between March 2007 and December 2020. Demographic, clinical, epidemiological, and mortality data were collected and analyzed. Major psychiatric comorbidities were evaluated according to ICD-9 and ICD-10 classifications. A total of 1325 intensive care unit burn patients were included. Suicide by burning was attempted in 45 cases (3.4%). Attempted suicide victims presented with significantly higher burn severity, reflected by higher abbreviated burn severity index scores, and larger TBSA affected. Burned TBSA ≥30% and inhalation injuries were observed more frequently in suicidal patients. These patients also experienced prolonged hospital and intensive care unit length of stay, required surgical interventions and mechanical ventilation more frequently, and had significantly longer periods on ventilation, causing an overall higher mortality rate (24.4%). Psychiatric comorbidities were present in 75.6% of patients who attempted suicide. Despite the low prevalence, burn severity and mortality are considerably high in patients who attempted suicide by burning, presenting a significant challenge for healthcare providers. The majority of patients had a history of psychiatric disorder, highlighting the importance of identifying patients at high-risk who may profit from increased psychiatric intervention.

Probabilistic inversion of audio-frequency magnetotelluric data and application to cover thickness estimation for mineral exploration in Australia

We have applied a Bayesian inference algorithm and released open-source code for the 1D inversion of audio-frequency magnetotelluric data. The algorithm uses a trans-dimensional Markov chain Monte Carlo technique to solve for a probabilistic resistivity-depth model. The inversion employs multiple Markov chains to generate an ensemble of millions of resistivity models that adequately fit the data given the assigned noise levels. The trans-dimensional aspect of the inversion means that the number of layers in the resistivity model is solved for rather than being predetermined. The inversion scheme favours a parsimonious solution and the acceptance criterion ratio is theoretically derived such that the Markov chain will eventually converge to an ensemble that is a good approximation of the posterior probability density (PPD). Once the ensemble of models is generated, its statistics are analysed to assess the PPD and to quantify model uncertainties. This approach gives a thorough exploration of model space and a more robust estimation of uncertainty than deterministic methods allow.We demonstrate the application of the method to cover thickness estimation for a number of regional drilling programs. Comparison with borehole results demonstrates that the method is capable of identifying major stratigraphic units with resistivity contrasts. Our results have assisted with drill site targeting and have helped to reduce the uncertainty and risk associated with intersecting targeted stratigraphic units in covered terrains. Interpretation of the audio-frequency magnetotelluric data has improved our understanding of the distribution and geometries of sedimentary basins. From an exploration perspective, mapping sedimentary basins and covered near-surface geological features supports the effective search for mineral deposits in greenfield areas.

Diversity and Relative Abundance of Ungulates and Other Medium and Large Mammals in Flooded Forests in the Dahomey Gap (Togo).

"The Dahomey Gap" is a human-derived mostly savannah region that separates the Guineo-Congolian rainforest block into two major units: the Upper Guinean and the Lower Guinean Forest blocks. Several forest patches are distributed throughout this savannah-dominated habitat. The mammal communities in the Dahomey Gap region have been poorly studied. In this paper we analyse the species richness and abundance of, as well as conservation implications for, medium and large mammals (especially ungulates) inhabiting a complex of flooded forests near the Mono river in south-eastern Togo. We use several field methods to describe the species richness of mammals in this area, including camera-trapping, recce transects, Kilometric Index of Abundance (KIA) estimates, examination of hunters' catches and face-to-face hunter interviews. Overall, we directly recorded 19 species that coexist in these forests. Based on interviews, nine other species were confirmed as present in the study area. Only five species were common: Cephalophus rufilatus, Tragelaphus scriptus, Chlorocebus aethiops, Atilax paludinosus and Herpestes ichneumon. The area still contains various threatened species such as Tragelaphus spekii and Hippopotamus amphibius. We stress that to ensure the protection of the Dahomey Gap mammals, it is important to seriously consider protecting not only the forest patches but also the surroundings, mainly savannah landscapes.

Cryo–electron microscopy structure of the H3-H4 octasome: A nucleosome-like particle without histones H2A and H2B

The canonical nucleosome, which represents the major packaging unit of eukaryotic chromatin, has an octameric core composed of two histone H2A-H2B and H3-H4 dimers with ∼147 base pairs (bp) of DNA wrapped around it. Non-nucleosomal particles with alternative histone stoichiometries and DNA wrapping configurations have been found, and they could profoundly influence genome architecture and function. Using cryo-electron microscopy, we solved the structure of the H3-H4 octasome, a nucleosome-like particle with a di-tetrameric core consisting exclusively of the H3 and H4 histones. The core is wrapped by ∼120 bp of DNA in 1.5 negative superhelical turns, forming two stacked disks that are connected by a H4-H4' four-helix bundle. Three conformations corresponding to alternative interdisk angles were observed, indicating the flexibility of the H3-H4 octasome structure. In vivo crosslinking experiments detected histone-histone interactions consistent with the H3-H4 octasome model, suggesting that H3-H4 octasomes or related structural features exist in cells.

Structural setting of the Zoujiashan-Julong’an region, Xiangshan volcanic basin, China, interpreted from modern CSAMT data

The Zoujiashan-Julong’an area is situated on the western side of the Xiangshan volcanic basin. The basin represents the central part of the Jiangxi Province and it is well endowed with uranium deposits. Ongoing brownfield exploration requires a better understanding of the deep-seated geological structures of the region so as to discover additional, but concealed, deposits at depth. Aiming at elucidating the deep structural and geological framework, 14 parallel controlled-source audio-frequency magnetotelluric (CSAMT) survey lines were conducted to document the relationships between lithological contacts, faults and uranium mineralization with a penetration depth of about 2 kms. By integrating the interpreted geological profiles with geological surface maps and drilling data, a 3D geological model was constructed by using GOCAD software. The 3D model illustrated the major lithological units, faults and concealed uranium mineralization, respectively. The obtained data show that: (1) The Ehuling Formation as well as the underlying metamorphic basement displays a medium-to-high resistivity, whereas the Daguding Formation has a low-resistivity. The unconformity surface between volcanic rocks and the metamorphic basement is represented by a distinct low-resistivity zone which is locally intersected by faults. The fault structure in the CSAMT inversed sections appears as a low resistivity zone or a high-low resistivity variation gradient zone cutting through different interfaces. (2) As is documented by the 3D geological model, the favorable sites for uranium mineralization are distributed in the depressions of the metamorphic rock basement, at the boundary of volcanic rock formations, and in the transitional zones between the depressions and uplifts, where the thickness of the strata increases (or decreases) and the composite faults exist. (3) The location and spatial distribution of the unexposed structures delineated by the 2D resistivity inversion results are consistent with the geological mapping results. The delineated interface between porphyritic lava and rhyodacite is basically consistent with the drilling data. The CSAMT detection results can provide reliable deep geological structure information for 3D geological mapping and deep metallogenic prediction in Xiangshan area.

Geomorphic Analysis of Baghain River, Yamuna Basin, and its Implication for Drainage Characteristic and Tectonics using Remote Sensing and GIS Techniques

Abstract The present study aims to access the geomorphic analysis of the Baghain river basin and its implication on landscape evolution. Baghain river originates from the Panna hill, and flows through marginal and central Ganga plain. It empties itself in to Yamuna river near Chilla village, Banda district, Uttar Pradesh. The river basin comprises of three major geological units associated with this basin: Bundelkhand gneissic complex, Vindhyan Supergroup (hard rock terrain known as Panna hill) and Alluvial deposit (marginal Ganga plain and central Ganga plain). The current work focuses on study of morphometric parameters and geomorphic indices of Baghain river basin using digital elevation model (DEM) and topographic maps (1:50,000 scale). This basin exhibits four types of drainage patterns: dendritic, parallel, trellis and rectangular. Bifurcations ratio (4.82) of river basin suggest that the most part of the basin is not influenced by any geological structures. The elongation ratio (0.50) suggests that the basin is moderately elongated. The drainage density (0.62) and stream frequency (0.22) also suggest that the basin has moderate to high permeable and easily erodible alluvium terrain. The escarpment height is low in the proximal part (Panna Hill) and high in the middle and distal parts of the basin (marginal Ganga plain and central Ganga plain, respectively. Asymmetric factor (52) shows a leftward tilt of the basin. The region lies under marginal Ganga plain, and Bundelkhand plateau. The sharp bend present is probably due to the lithological variation. It reflects moderate gradient in the upper part (Panna hill), steep gradient in the lower part (Panna hill), and low gradient in the marginal to central Ganga plain.

A Study on the Proper Residential Area Standard based on the Analysis of Housing Status of Apartment Residents

This study diagnosed the problems of the current minimum housing status of apartment residents, which is Korea’s representative housing type, and reviewed regulations related to housing standards in foreign countries to suggest the necessity and direction of the proper housing area. A survey was conducted on 856 residents in the metropolitan area to understand the housing status of apartment residents, and the criteria for overseas housing area were investigated and analyzed through domestic statistical data and overseas literature data to review the minimum housing standard. Through the review of the above, this study presented the following three conclusions. 1) It is necessary to review the minimum residential area in which single-person households are recognized as independent and permanent household types, not temporary households, and the lifestyle of single-person households is normally reflected. 2) As the gap between the minimum residential area and the actual residential status by household type is significant, an proper residential area should be introduced to reflect the reality. 3) It is necessary to calculate the residential area based on the adult standard and the total residential area based on the proper area for each major unit space in the house for introducing an proper residential area.

Molecular structural dataset of lignin macromolecule elucidating experimental structural compositions

Lignin is one of the most abundant biopolymers in nature and has great potential to be transformed into high-value chemicals. However, the limited availability of molecular structure data hinders its potential industrial applications. Herein, we present the Lignin Structural (LGS) Dataset that includes the molecular structure of milled wood lignin focusing on two major monomeric units (coniferyl and syringyl), and the six most common interunit linkages (phenylpropane β-aryl ether, resinol, phenylcoumaran, biphenyl, dibenzodioxocin, and diaryl ether). The dataset constitutes a unique resource that covers a part of lignin’s chemical space characterized by polymer chains with lengths in the range of 3 to 25 monomer units. Structural data were generated using a sequence-controlled polymer generation approach that was calibrated to match experimental lignin properties. The LGS dataset includes 60 K newly generated lignin structures that match with high accuracy (~90%) the experimentally determined structural compositions available in the literature. The LGS dataset is a valuable resource to advance lignin chemistry research, including computational simulation approaches and predictive modelling.

Impact of sarcopenia on the surgical outcomes in patients with hepatolithiasis: A multicenter 10-year experience

BackgroundThe impact of sarcopenia on the surgical outcomes of hepatectomy for hepatolithiasis has not been investigated. The present study elucidated the effect of sarcopenia on short-term outcomes after hemihepatectomy for hepatolithiasis and investigated the benefit of different surgical approaches to hepatectomy in patients with sarcopenia. MethodsPatients who underwent hemihepatectomy for hepatolithiasis at Fujian Provincial Hospital and 5 other medical centers from 2010 to 2020 were enrolled. The sarcopenic obesity subgroup had sarcopenia coexisting with obesity, and the sarcopenic nonobesity subgroup had sarcopenia without obesity. We analyzed the postoperative outcomes of the sarcopenia group, sarcopenic obesity subgroup and sarcopenic nonobesity subgroup and the corresponding benefits of different surgical approaches. ResultsPatients with sarcopenia (n = 481) had worse surgical outcomes than nonsarcopenia, such as longer postoperative hospital duration of stay, longer time to oral intake, longer time to bowel movement, and longer time to off-bed activities. In postoperative short-term outcomes, we also found that sarcopenia had higher rates of major complications, bile leakage, and intensive care unit occupancy than the nonsarcopenic group. Subgroup analysis showed that sarcopenic obesity subgroup (n = 182) had the worst results in intraoperative outcomes and postoperative short-term outcomes. Multivariate analysis identified sarcopenic obesity as a significant risk factor for postoperative hospital duration of stay (hazard ratio = 2.994, P < .001). Furthermore, the sarcopenic obesity and sarcopenic nonobesity (n = 299) subgroups benefited from laparoscopic surgery compared with open surgery, including postoperative recovery and major complications (all P < .05). However, sarcopenic nonobesity subgroup had more significant benefits of laparoscopy than the sarcopenic obesity subgroup. The learning curve for laparoscopic hemihepatectomy for the sarcopenic obesity subgroup had a plateau, and the surgical outcomes of the sarcopenic obesity subgroup were closer to the sarcopenic nonobesity subgroup after the plateau. ConclusionSarcopenia is associated with more adverse events after hepatectomy and patients with sarcopenic obesity have a higher incidence of adverse events. Patients with sarcopenia could benefit from laparoscopy. Compared with the sarcopenic obesity patients, the sarcopenic nonobesity patients benefited more from laparoscopy. Although the sarcopenic obesity patients had more complications and slower postoperative recovery than the sarcopenic nonobesity patients, laparoscopic also could improve their short-term outcomes, but a longer learning curve was required.

Geochemistry of volcanic rocks and dykes from the Remeshk-Mokhtarabad and Fannuj-Maskutan Ophiolites (Makran Accretionary Prism, SE Iran): New constraints for magma generation in the Middle East neo-Tethys

The Remeshk-Mokhtarabad and Fannuj-Maskutan ophiolites represent two major ophiolitic units in the North Makran Domain (Makran Accretionary Prism). Volcanic rocks and dykes of these ophiolites mainly consist of basalts and rare basaltic andesites, andesites and dacites. No chemical distinction can be seen in basalts from these two ophiolitic units, or between volcanic rocks and dykes. Basaltic rocks show a broad MORB-type nature but variable chemical composition (e.g., SiO2= 42.64–52.63 wt%; TiO2= 0.98–2.43 wt%; Mg# = 71–50). They show both N-MORB (Type 1) and E-MORB (Type 2) compositions (MORB: mid-ocean ridge basalt; N: normal; E: enriched). Type 1 rocks are very rare in both ophiolitic units, whereas Type 2 rocks are predominant. Type 1 rocks show low Th (0.10–0.16 ppm), Nb (1.86–2.82 ppm), Ta (0.09–0.17 ppm) abundance and low (La/Yb)N (0.50–0.75), (La/Sm)N (0.48–0.72) ratios. Compared to N-MORBs, Type 2 basalts show slight enrichment in Th (0.42–1.60 ppm), Nb (6.09–14.6 ppm), and Ta (0.227–0.792 ppm), as well as (La/Yb)N and (La/Sm)N ratios >1 like those observed in typical E-MORB. Trace element petrogenetic models indicate that primitive basalts derived from partial melting of a heterogeneous sub-oceanic mantle variably metasomatized by plume-type (OIB-) components. Type 1 basalts derived from partial melting of mantle regions with no enrichment in OIB-type components, whereas Type 2 basalts derived from partial melting of DMM sources variably enriched by OIB-components. These rocks formed in an oceanic basin that was strongly affected by mantle plume activity and different extents of plume-ridge interaction.

Medical termination of pregnancy for fetal anomaly at or beyond 20weeks' gestation-What are the maternal risks?

To evaluate the common and severe maternal morbidities associated with medical termination of pregnancy (MTOP) for fetal anomaly ≥20weeks' gestation. A 10-year retrospective cohort study (January 2010-December 2019) analyzing 407 consecutive singleton pregnancies MTOP for fetal anomaly ≥20weeks' gestation, at a quaternary maternity centre in Australia (Royal Women's Hospital, Melbourne). The cohort comprised of 191 primiparous and 216 multiparous women, of whom 75 (34.7%) had at least one prior Cesarean; 13 women had a low-lying placenta or placenta praevia. The average gestation was 23weeks (interquartile range 22-26weeks). A spontaneous unassisted vaginal delivery was achieved by the majority (n=403, 99.0%). The most common maternal morbidities were transferred to the theater for manual removal of retained placental tissue (n=65, 16.0%) and postpartum haemorrhage (PPH) (n=45, 11.1%). Severe maternal morbidity occurred in six cases (1.3%) and included amniotic fluid embolism, cardiac arrest, major obstetric haemorrhage, uterine rupture and intensive care unit admission. There were no maternal deaths. The most common complications of MTOP for fetal anomaly ≥20weeks' gestation were manual removal of placenta and PPH. Severe maternal morbidity affected 1 in 81 women.

Biogeochemical behaviour of geogenic As in a confined aquifer of the Sologne region, France.

Arsenic (As) is one of the main toxic elements of geogenic origin that impact groundwater quality and human health worldwide. In some groundwater wells of the Sologne region (Val de Loire, France), drilled in a confined aquifer, As concentrations exceed the European drinking water standard (10μgL-1). The monitoring of one of these drinking water wells showed As concentrations in the range 20-25μgL-1. The presence of dissolved iron (Fe), low oxygen concentration and traces of ammonium indicated reducing conditions. The δ34SSO4 was anticorrelated with sulphate concentration. Drilling allowed to collect detrital material corresponding to a Miocene floodplain and crevasse splay with preserved plant debris. The level that contained the highest total As concentration was a silty-sandy clay containing 26.9mgkg-1 As. The influence of alternating redox conditions on the behaviour of As was studied by incubating this material with site groundwater, in biotic or inhibited bacterial activities conditions, without synthetic organic nutrient supply, in presence of H2 during the reducing periods. The development of both AsV-reducing and AsIII-oxidising microorganisms in biotic conditions was evidenced. At the end of the reducing periods, total As concentration strongly increased in biotic conditions. The microflora influenced As speciation, released Fe and consumed nitrate and sulphate in the water phase. Microbial communities observed in groundwater samples strongly differed from those obtained at the end of the incubation experiment, this result being potentially related to influence of the sediment compartment and to different physico-chemical conditions. However, both included major Operating Taxonomic Units (OTU) potentially involved in Fe and S biogeocycles. Methanogens emerged in the incubated sediment presenting the highest solubilised As and Fe. Results support the hypothesis of in-situ As mobilisation and speciation mediated by active biogeochemical processes.

Successional development of wood-inhabiting fungi associated with dominant tree species in a natural temperate floodplain forest

Fungi play a crucial role in dead wood decay, being the major decomposers of wood and affecting microbiota associated with dead wood. We sampled dead wood from five deciduous tree species over more than forty years of decay in a natural European floodplain forest with high tree species diversity. While the assembly of dead wood fungal communities shows a high level of stochasticity, it also indicates clear successional patterns, with fungal taxa either specific for early or late stages of wood decay. No clear patterns of fungal biomass content over time were observed. Out of 220 major fungal operational taxonomic units, less than 8% were associated with a single tree species, most of them with Quercus robur . Tree species and wood chemistry, particularly pH, were the most important drivers of fungal community composition. This study highlights the importance of dead wood and tree species diversity for preserving the biodiversity of fungi. • Tree species-rich floodplain forest shows high diversity of wood fungi on dead wood. • Most fungi show low specificity and inhabit wood of multiple hardwood tree species. • Tree species-specific fungi are more abundant in early and late decomposition stages. • Fungal communities of deadwood are most affected by tree species and wood chemistry. • Fungal community assembly is largely stochastic but shows tractable succession.

Petrology of the magmatic system beneath Osorno volcano (Central Southern Volcanic Zone, Chile)

Petrological studies of volcanic systems and magmatic processes provide small-scale information that are inaccessible to the current resolution of geophysical tools. In the Southern Volcanic Zone of the Chilean arc, Osorno ranks sixth in the official risk classification in a region of increasing vulnerability due to soaring human activities coupled with lahar hazard and the threat of a tsunami induced by a flank collapse. However, its magmatic system remained poorly investigated. Here, we present and integrate to existing geophysical models a comprehensive set of petrographic and geochemical data including whole-rock and mineral major and trace element analyses, associated with detailed numerical modelling to constrain the storage conditions below Osorno. To capture the full complexity of the system, over 154 samples of all known major units of the volcano have been collected. They cover a large range from tholeiitic primary basalt (Mg# = 0.72 and ≥ 50 wt% SiO 2 ) to rhyodacite (Mg# = 0.18 and ≥ 70 wt% SiO2), displaying a compositional gap within andesite (59–63 wt% SiO 2 ). This gap results either from andesitic melt thermal instability or from the interstitial melt extraction of the crystal mush. Basalt and basaltic andesite lava with plagioclase and olivine (± clinopyroxene) are dominant. Their crystallinity largely varies from 1 to 53 area % with the lowest values in the most evolved basaltic andesites. Dacites are limited to three small domes with low crystallinities between 7 and 13 area %. The presence of diktytaxitic enclaves within the dacites indicate minor mingling with a less differentiated melt. Water-bearing phases are generally absent, except for one dacite sample where few small amphibole crystals occur. Petrology, chemical data and thermobarometric results imply shallow fractional crystallization of troctolitic, gabbroic and gabbronoritic cumulates. Differentiation dominantly takes place between 2 and 3 kbar (6–10 km) and results from a water-poor (≈1 wt% H 2 O), tholeiitic parental melt. No evidence of high-pressure fractionation was observed. We interpret this differentiation depth as Osorno's main storage zone. It correlates with the depth of the intracrustal discontinuity and seismic reports below the volcano. Only the upper half of the storage zone, imaged with geophysical methods, was erupting. We suggest a comparable behavior for a potential future event. • Basalt evolves to dacite at ≈2 kbar near the depth of the intracrustal discontinuity. • Fractional crystallization dominates under water undersaturated conditions. • Petrographic observations and numerical models were integrated with geophysical data.

Hospital Acquired Complications in South Australian major public hospitals.

The prevalence of Hospital Acquired Complications (HACs) within major hospitals and intensive care units (ICUs) is often used as an indication of care quality. We performed a retrospective cohort study of acute care separations from four adult public hospitals in the state of South Australia, Australia. Data were derived from the Integrated South Australian Activity Collection (ISAAC) database, subdivided into those admitted to ICU or non-ICU (Ward) in tertiary referral or (other major) metropolitan hospitals. During the five-year study period (1 July 2013 to 30 June 2018), there were 471,934 adult separations with 65,133 HAC events reported in 43,987 (9.32%) at a mean rate of 13.8 (95% confidence interval (CI) 13.7 to 13.9) HAC events per 100 separations and 18.5 (95% CI 18.4 to 18.7) per 1000 bed days. The Ward cohort accounted for the majority (430,583 (91.2%)) of separations, in-hospital deaths (6928 (66.4%)) and HAC events (29,826 (67.8%)). The smaller ICU cohort (41,351 (8.76%)) had a higher mortality rate (8.46% versus 1.61%; P < 0.001), longer length of stay (median 10.0 (interquartile range (IQR) 6.0-18.0) days versus 4.0 (IQR 3.0-8.0) days P < 0.001), and higher HAC prevalence (62.1 (95% CI 61.3 to 62.9) versus 9.16 (95% CI 9.07 to 9.25) per 100 separations P < 0.001). Both ICU and Ward HAC prevalence rates were higher in tertiary referral than major metropolitan hospitals (P < 0.001). In conclusion, higher HAC prevalence rates in the ICU and tertiary referral cohorts may be due to high-risk patient cohorts, variable provision of care, or both, and warrants urgent clinical investigation and further research.

Geochemical studies of the Green River Formation in the Piceance Basin, Colorado

Hierarchical cluster analysis (HCA) was applied to a geochemical dataset representing the Eocene Green River Formation in the Piceance Basin of Colorado to identify chemofacies in core and outcrop samples from the basin margin and the basin center. The input dataset consisted of inductively coupled plasma optical emission spectroscopy and mass spectrometry and total organic carbon (TOC) content analyses of 186 basin margin outcrop samples and 190 basin center core samples discussed in Part 1 of this study (this volume). TOC values and twenty-five major and trace elements were used as variables to define statistical clusters of samples for the overall dataset, for the two basin center cores, and for each separate core or outcrop dataset by HCA applying Euclidean distance and Ward’s method algorithms. For each dataset, five cluster-defined chemofacies were identified. The chemofacies for each dataset show chemical affinities with five informally defined rock types– mudstone, marlstone, carbonate-rich mudstone, siliciclastic-rich mudstone/siltstone/sandstone, and Na-rich (saline) mudstone, with each showing variations in TOC content and abundance of redox sensitive minor and trace elements. A close relationship between enrichment of redox sensitive elements, particularly As and Mo, and TOC is identified in the basin center. Whereas enrichment factors (relative to average shale) are relatively low for many Period IV (PIV) transition metals, as discussed in Part 1 of this study, their consistent coherence in enrichment or depletion in HCA-defined chemofacies demonstrates the expected relationship between redox state and organic richness. Enrichment in PIV transition metals also shows a correlation to enrichment in elements with affinity for siliciclastic sediment. Enrichment/depletion among several groups of redox indicators is not everywhere consistent, with some chemofacies showing, for example, enrichment of PIV transition metals and depletion of sulfur and arsenic. Early timing of saline conditions in the basin margin is clearly displayed in the chemofacies log display, consistent with observations based on geochemical interpretations of concentrations and elemental ratios discussed in Part 1. Overall, the chemofacies are consistent with major mineralogical units and lake history stages defined in previous work, but provide more detail on the fluctuations in lake chemistry that occurred during deposition of Green River oil shale in the Piceance Basin.

Theoretical and experimental investigations on steady-state responses of rotor-blade systems with varying rotating speeds based on a new nonlinear dynamic model

Rotor-blade systems are major units in turbine structures, whose dynamic responses will affect structural safety, energy conversion efficiency, overall durability and service performance. During high-speed rotation, periodic disturbances near resonant regions may lead to a large deflection of flexible blades and an unstable rotation of rotor-blade systems. Due to the coupling effect of rotation and vibration, the distributions of mass/inertia, damping and stiffness are related with varying rotation speed and local deformation in rotor-blade systems, which has not been concerned in conventional harmonic balance methods. In this paper, a modified harmonic balance method is proposed to obtain dynamic responses of rotor-blade systems with a comprehensive model in incremental form, which considers geometric nonlinearity, centrifugal and gyroscopic effects of flexible blades and nonlinear constraints between rotor and multiple blades. Based on Reddy’s high order shear deformation plate theory, dynamic equations for a rotating composite blade with a pre-setting angle is established with consideration of von Kármán type geometrical nonlinearity, varying rotating speeds and equivalent aerodynamic loads. A coupling motion equation for rotor-blade systems is derived out by assembling corresponding elemental equilibrium and joint nonlinear constraints. Steady-state responses are obtained by using a modified harmonic balance method which accounts nonlinearities of mass, damping and stiffness. Numerical and experimental studies for rotor-blade systems are carried out to validate the effectiveness of the proposed model. Results show that a higher rotating speed leads to larger natural frequencies of rotor-blade systems, and a more evidently coupling effect between motion and vibration. Meanwhile, joint constraints, damping effect and load distributions have evident influences on vibration amplitudes and resonant points of system’s steady-state responses.