Thermodynamic Components Research Articles

ПРО ЛІТОФЛЮЇДОТЕРМОДИНАМІЧНУ СИСТЕМУ В ГЕОЛОГІЇ І ГЕОХІМІЇ

The researcher’s approaches to the term “fluid systems” as a prototype of the fluid medium of crystallization of minerals, naturally preserved relics – inclusions of fluids reflect the features of the fluid regime of mineralogenesis of rock-ore complexes are analyzed. It is emphasized that the term “fluid” characterizes the main property of the substance of the medium of mineralogenesis, the most important substance of the Earth’s crust, its highest mobility, the maximum disorder of structure, fluidity, and covers the liquid or gas state of the lightweight components (gas, aqueous solution), as well as the melt of magmatic (silicate, salt, carbonate) substance. Under the fluid regime, the author understands the physical and chemical nature, the spatial-temporal sequence of manifestation and the variability of the parametric characteristics of the fluids, that is, the entire set of physico-chemical and geological phenomena and processes that determine the regular (discrete, periodic, evolutionary) changes in aggregate state, PT-parameters and the composition of the fluid medium of crystallization of minerals and their identified (certain, specific) parageneses. Our long-term studies show that the physico-chemical system of the fluid medium of mineral-ore-narhtidgenesis should cover lithoid (rocky), fluid (genetic) and thermodynamic (temperature, pressure, concentration) components that determine the mass, heat and the energy exchange between the fluid and of its host rock. In view of this, we define this physico-chemical system as a “lithofluid and thermodynamic system” and we believe that this definition takes into account all known phenomena of generation, migration, differentiation and accumulation of fluids, in particular hydrocarbons (hydrocarbon-containing), in the lithosphere of the Earth. An example of such a lithofluid and thermodynamic system in the Earth’s bowels – the natural high-energy physicochemical reactor is the hydrocarbon-generating and mineral-ore-forming system of the deep abiogenic high-termobaric fluid.

Future Changes in East Asian Summer Monsoon Circulation and Precipitation Under 1.5 to 5 °C of Warming

AbstractUnderstanding the link between future changes in East Asian summer monsoon (EASM) and global warming levels is of great importance for regional climate change adaptation and mitigation in East Asia. Here, we analyze the projected changes in EASM circulation and precipitation under different warming levels from 1.5 to 5 °C above the preindustrial global mean temperature, using large‐ensemble simulations conducted with Canadian Earth System Model version 2. We find that the model projects enhanced monsoon circulation and precipitation with global warming. The 850‐hPa meridional winds, precipitation, and 500‐hPa vertical ascending motion will be enhanced nonlinearly, while the total column precipitable water will increase quasi‐linearly. The increase in precipitable water in the wet EASM region is only slightly greater than global average but the increase in precipitation is much greater than global one, with enhanced 500‐hPa vertical ascending motion contrary to global mean. The increased low‐level land‐sea thermal contrast leads to the enhanced EASM meridional circulation and thus bring a large amount of moisture into Eastern China, providing favorable conditions for additional increase in precipitation. A simplified moisture budget analysis shows that the dynamic component related to strengthening monsoon circulation plays dominant role in the increase in EASM precipitation when the global temperature increases by more than approximately 2 °C, while the thermodynamic component caused by increased water vapor is important when the warming is smaller.

Understanding Monsoonal Water Cycle Changes in a Warmer Climate in E3SMv1 Using a Normalized Gross Moist Stability Framework

AbstractOne of the grand challenges of climate science is understanding the changes of the tropical rain belts and monsoon systems owing to CO2‐induced warming. A promising path forward links the fluxes of energy and moisture to tropical circulation features. To this end, we make use of the Energy Exascale Earth System Model version 1, where the divergence of moist static energy and moisture have been calculated online, and employ a normalized gross moist stability (NGMS) diagnostic framework to understand the linkages between changes in the flow of energy and moisture within the monsoons. We focus on the Asian Summer Monsoon system and utilize a series of atmosphere‐land and atmosphere‐land‐ocean simulations to understand the connection between fluxes and monsoons. Uncoupled simulations with prescribed sea surface temperatures indicate that decreases in NGMS over land are important in explaining precipitation increases in response to both sea surface temperature and CO2 increases. In fully coupled experiments, NGMS decreases remain an important contributor to the increase in P‐E, but the coupled simulations highlight the importance of consistent ocean and land responses in interpreting the monsoon changes. This study indicates that transient eddy fluxes play an important role in NGMS decreases and that a time‐mean view of the monsoon circulations is insufficient to quantify the link between future changes in the fluxes of energy and moisture. Compensation between dynamic and thermodynamic components of vertical moist static energy advection occurs, with the thermodynamic contribution dominating. The compensation is shown to be sensitive to relative humidity, with higher relative humidity leading to a stronger thermodynamic component.

Attribution of the East Asian Winter Temperature Trends During 1979–2018: Role of External Forcing and Internal Variability

AbstractAttributing the surface air temperature (SAT) trends at regional scale to internally generated and externally forced components is a major challenge. Based on the observations and ensemble simulations of climate models, we apply a “dynamical adjustment” methodology to estimate quantitatively the contribution of the internal and forced dynamic and thermodynamic components to the East Asian winter SAT trends during 1979–2018. The observed winter SAT trends are strongly influenced by internal variability, especially in the northern East Asia (NEA). The internal component of observed SAT trends is largely dynamically induced, whereas the forced component is controlled by thermodynamics. The internally generated variability offsets the forced warming by more than 70% in the NEA, leading to a weak observed warming in the NEA. In contrast, internal contributions are small in the southern East Asia. The internally generated SAT changes in the NEA are closely tied to the multidecadal changes of Arctic Oscillation.

Decomposition of Future Moisture Flux Changes over the Tibetan Plateau Projected by Global and Regional Climate Models

AbstractTo meet the requirement of high-resolution datasets for many applications, a dynamical downscaling approach using a regional climate model (the WRF Model) driven by a global climate model (CCSM4) has been adopted. This study focuses on projections of future moisture flux changes over the Tibetan Plateau (TP). First, the downscaling results for the historical period (1980–2005) are evaluated for precipitation P, evaporation E, and precipitation minus evaporation P − E against Global Land Data Assimilation System (GLDAS) data. The mechanism of P − E changes is analyzed by decomposition into dynamic, thermodynamic, and transient eddy components. Whether the historical period changes and mechanisms continue into the future (2010–2100) is investigated using the WRF and CCSM model projections under the RCP4.5 and RCP8.5 scenarios. Compared with coarse-resolution forcing, downscaling was found to better reproduce the historical spatial patterns and seasonal mean of annual average P, E, and P − E over the TP. WRF projects a diverse spatial variation of P − E changes, with an increase in the northern TP and a decrease in the southern TP, compared with the uniform increase in CCSM. The dynamic component dominates P − E changes for the historical period in both the CCSM and WRF projections. In the future, however, the thermodynamic component in CCSM dominates P − E changes under RCP4.5 and RCP8.5 from the near-term (2010–39) to the long-term (2070–99) future. Unlike the CCSM projections, the WRF projections reproduce the mechanism seen in the historical period—that is, the dynamic component dominates P − E changes. Furthermore, future P − E changes in the dynamical downscaling are less sensitive to warming than its coarse-resolution forcing.

A Methodology for the Experimental Validation of an Aircraft ECS Digital Twin Targeting System Level Diagnostics

The Environmental Control System (ECS) of an aircraft is responsible for regulating and conditioning the airflow into the cockpit, cabin and avionics bay. The ECS is composed of several complex sub-systems and components that are reported as key unscheduled maintenance drivers for legacy aircraft by aircraft operators. Furthermore, the incorporated temperature and flow control valves in these sub-systems have the capability to mask potential faults at the component level, making the diagnostic process very challenging. To overcome this challenge, the aviation industry is currently proactively exploring the predictive maintenance approach that allows real-time monitoring of the key systems, sub-systems and components. In the context of the ECS, this necessitates the requirement to equip the system with appropriate condition monitoring capabilities. To do this, the performance characteristics of the ECS at sub-system and component level needs to be well understood under a wide-range of aircraft operating scenarios. Existing literature provides component level and system level analyses of the ECS. However, it lacks an experimentally verified and validated ECS sub-system and component level simulation tool (ECS Digital Twin), capable of simulating the thermodynamic performance and component health state parameters under wide-ranging aircraft operational scenarios. The ECS Digital Twin (DT) developed by the Cranfield University IVHM Centre offers the capability to simulate healthy and faulty cases of the Passenger Air Conditioner (PACK). This paper proposes a methodology for full-scale experimental Verification & Validation (V&V) of the developed ECS DT, to enable component level simulation, and enabling accurate diagnostics, of the civil aircraft ECS. The paper reports on progress to date in this project.

Using Near-Ground Storm Relative Helicity in Supercell Tornado Forecasting

Abstract This study examines the possibility that supercell tornado forecasts could be improved by utilizing the storm-relative helicity (SRH) in the lowest few hundred meters of the atmosphere (instead of much deeper layers). This hypothesis emerges from a growing body of literature linking the near-ground wind profile to the organization of the low-level mesocyclone and thus the probability of tornadogenesis. This study further addresses the ramifications of near-ground SRH to the skill of the significant tornado parameter (STP), which is probably the most commonly used environmental indicator for tornadic thunderstorms. Using a sample of 20 194 severe, right-moving supercells spanning a 13-yr period, sounding-derived parameters were compared using forecast verification metrics, emphasizing a high probability of detection for tornadic supercells while minimizing false alarms. This climatology reveals that the kinematic components of environmental profiles are more skillful at discriminating significantly tornadic supercells from severe, nontornadic supercells than the thermodynamic components. The effective-layer SRH has by far the greatest forecast skill among the components of the STP, as it is currently defined. However, using progressively shallower layers for the SRH calculation leads to increasing forecast skill. Replacing the effective-layer SRH with the 0–500 m AGL SRH in the formulation of STP increases the number of correctly predicted events by 8% and decreases the number of missed events and false alarms by 18%. These results provide promising evidence that forecast parameters can still be improved through increased understanding of the environmental controls on the processes that govern tornado formation.

A bias-corrected projection for the changes in East Asian summer monsoon rainfall under global warming

Projecting regional rainfall changes in a warmer climate attracts ongoing attention. However, large uncertainty still exists in multi-model projection. In this study, we introduce a bias-corrected method to correct the multi-model projection of changes in East Asian summer monsoon (EASM) rainfall based on the historical and RCP8.5 runs of 25 models from phase 5 of Coupled Model Intercomparison Project. Firstly, the total rainfall changes are separated into the thermodynamic component due to increased specific humidity and the dynamic component due to circulation changes. The thermodynamic component is corrected using the observed present-day rainfall and the increase rate of specific humidity based on the wet-get-wetter mechanism. On the other hand, the dynamic component with the circulation changes is corrected based on a “spatial emergent constraint” method, which is further validated by the perfect model approach. Together, these corrections give an integrated projection for EASM rainfall changes under global warming. Such an approach can improve the signal-to-noise ratio of projection effectively, from the original 0.73 of the multimodel mean to around 1.9. The corrected projection of EASM rainfall changes shows a pronounced increase in southern China, the northwest Pacific and a belt from northern China to northeastern China, and a weak increase in other EASM regions.

The Extreme Precipitation Index (EPI): A Coupled Dynamic–Thermodynamic Metric to Diagnose Midlatitude Floods Associated with Flow Reversal

Abstract The extreme precipitation index (EPI) is a coupled dynamic–thermodynamic metric that can diagnose extreme precipitation events associated with flow reversal in the mid- to upper troposphere (e.g., Rex and omega blocks, cutoff cyclones, Rossby wave breaks). Recent billion dollar (U.S. dollars) floods across the Northern Hemisphere midlatitudes were associated with flow reversal, as long-duration ascent (dynamics) occurred in the presence of anomalously warm and moist air (thermodynamics). The EPI can detect this potent combination of ingredients and offers advantages over model precipitation forecasts because it relies on mass fields instead of parameterizations. The EPI’s dynamics component incorporates modified versions of two accepted blocking criteria, designed to detect flow reversal during the relatively short duration of extreme precipitation events. The thermodynamic component utilizes standardized anomalies of equivalent potential temperature. Proof-of-concept is demonstrated using four high-impact floods: the 2013 Alberta Flood, Canada’s second costliest natural disaster on record; the 2016 western Europe Flood, which caused the worst flooding in France in a century; the 2000 southern Alpine event responsible for major flooding in Switzerland; and the catastrophic August 2016 Louisiana Flood. EPI frequency maxima are located across the North Atlantic and North Pacific mid- and high latitudes, including near the climatological subtropical jet stream, while secondary maxima are located near the Rockies and Alps. EPI accuracy is briefly assessed using pattern correlation and qualitative associations with an extreme precipitation event climatology. Results show that the EPI may provide potential benefits to flood forecasters, particularly in the 3–10-day range.

Is There a Relationship between Energy, Amount of Information and Temperature?

Aims: To use the generally accepted formulas linking energy, temperature and information, and not requiring any additional restrictions, to introduce a practical numerical value of the energy of any specific object based on the amount of information and thermodynamic temperature.
 Place and Duration of Study: Beer-Sheba, between January 2019 and July 2019.
 Methodology: By combining the Landauer limit and Bekenstein’s proof that the amount of information of any physical system must be finite, if the object space and its energy are finite, the values of energy-matter and energy, based on the amount of information, were calculated for various elements of nature. In addition, a formula is presented for the energy of the universe containing these two components.
 Results: The energy content of an object depends not only on its mass and speed. The value of the additional independent component, due to the amount of information contained in the object, is caused by its size and the ambient temperature. This component has never been considered in the scientific literature. This means that energy is inextricably linked with both the space and the thermodynamic component of Nature.
 Conclusion: Using the generally accepted formulas linking energy, temperature and information and not requiring any additional restrictions, we have shown that it is possible to represent the energy of the universe on the basis of information theory.

Structural and binding insights into HIV-1 protease and P2-ligand interactions through molecular dynamics simulations, binding free energy and principal component analysis

HIV-1 protease (HIV-1-pr) plays an important role in viral replication and maturation, making it one of the most attractive targets for anti-retroviral therapy. To design new effective inhibitors able to combat drug resistance in mutant HIV-1-pr variants, it is essential to gain further understanding about the mechanisms by which the recently proposed inhibitors deactivate the mutant HIV-1-pr variants. In the present work, we explored the interactions between two P2-ligands (DRV, and one new derivative, 4UY) with wild type (WT) and two multiple mutant HIV-1-pr variants (p20 and p51) with all atom molecular dynamics (MD) simulations, binding free energy calculations, and principal component analysis (PCA). The trajectories of MD simulations show that both 4UY and DRV primarily bind with the active sites, flap and 80s loop regions of HIV-1-pr variants through either hydrogen bonds or hydrophobic interactions. More hydrogen bonds and hydrophobic interactions were located for 4UY/HIV-1-pr complexes than for DRV/HIV-1-pr counterparts. More importantly, 4UY was found to have an extra hydrogen bond with the backbone of Gly48’ in the flap region of the HIV-1-prs. The flap tip-tip distance (I50–I50’) and flap tip-active site distance (I50-D25 and I50′-D25’) indicate that the flaps turn more closed in 4UY bound HIV-1-prs than DRV bound ones, and the former also have more compact hydrophobic cavities than the latter. Further, the vector projections from PCA indicate that 4UY/DRV inhibitor binding projects the closing of flap in HIV-1-pr variants. In line with the above trajectory analysis, the thermodynamics calculation with MM-PBSA method suggests much stronger binding affinity for 4UY/HIV-1-pr than DRV/HIV-1-pr by 4.3–6.4 kcal/mol. Although p20 and p51 also induce weaker binding due to multiple mutants for 4UY inhibitor by 1.9–1.8 kcal/mol, their bindings to the new P2 ligand (4UY) are indeed significantly enhanced as compared to DRV. The thermodynamic components responsible for the binding differences and the contribution from key residues to the binding were also discussed in detail.

Can the weakening of Indian Monsoon be attributed to anthropogenic aerosols?

Literature found that the increasing concentration of Anthropogenic Aerosol (AA) is the key reason behind the weakening trend of Indian Summer Monsoon Rainfall (ISMR), based on the Coupled Model Intercomparison Project Phase5 (CMIP5) simulations with AA-only forcing. Here, we re-examine and find that AA-only simulations show country-wide drying, in contrast to the observed east-west asymmetry in the recent ISMR trend. For further evaluation, we decompose the changes in moisture convergence during summer monsoon into dynamic and thermodynamic components. We find that multi-run ensemble averages for individual CMIP5 models do not capture the observed dominance of the changes in dynamic component over the thermodynamic one. An optimal fingerprinting technique for detection and attribution also fail to attribute the changes in ISMR to AA, either because of large internal variability and/or intermodel spread. This implies the need for more careful assessment of AA-only simulations for the ISMR before attributing the changes to AA.

Disentangling the Changes in the Indian Ocean Dipole–Related SST and Rainfall Variability under Global Warming in CMIP5 Models

AbstractThis study disentangles the changes in Indian Ocean (IO) dipole (IOD)-related SST and rainfall variability under global warming projected by the RCP8.5 runs in 29 CMIP5 models. The IOD rainfall changes consist of the thermodynamic component due to the surface moisture increase and the dynamic component due to the changes in IOD-related circulation. The IOD circulation changes are dominated by the IOD SST changes, which were further clarified using the amplitude and structural decomposition. The amplitudes of IOD SST and circulation are both decreased at rates of around 7.2% and 13.7% °C−1, respectively. The structural changes in IOD SST and circulation show a pattern with increases from the eastern to the western coast of the equatorial IO, similar to the pattern of so-called extreme IOD events in previous studies. Disentangling previous mechanisms and projections, we conclude that the increased atmospheric stability suppresses the amplitudes in IOD SST and circulation, whereas the positive IOD (pIOD)-like mean-state SST changes, leading to greater warming in the west than the east, mainly alter the structure of IOD SST and circulation. Both the amplitude and structural changes in the IOD SST and circulation are robust among the CMIP5 models, but their distinct patterns and out-of-step changes lead to an uncertain projection of IOD changes defined by the dipole mode index or EOF analysis in previous studies. Furthermore, the structural changes, dominated by the pIOD-like mean-state SST changes, are significantly correlated with the historical IOD amplitude among the models. Considering the commonly overestimated IOD amplitude as an emergent constraint, the structural changes in IOD SST and circulation should not be as robust as the original multimodel projection.

Effect of the Ionic Environment on the Supramolecular Structure and Thermodynamics of DNA Gels

We report osmotic swelling pressure and small angle neutron scattering (SANS) measurements made on DNA gels prepared in 40 mM NaCl solution. Two series of gels were made: in the first the crosslinks were introduced in the absence of CaCl2, while in the second the DNA was crosslinked in solutions containing 40 mM NaCl with different amounts of CaCl2. The swelling pressure of the gels was determined as a function of the DNA concentration at constant salt concentrations. It was found that gels prepared in the presence of CaCl2 exhibited significantly lower swelling pressure than the corresponding gels made in CaCl2 free solutions. SANS revealed the presence of large clusters (>1000 Å) dominating the scattering signal at low values of q. In the intermediate q‐range the SANS intensity varied as q−1, in agreement with the linear character of the DNA chains. From the SANS response in the high q region the thermodynamic component of the concentration fluctuations, Idyn(0), was estimated. It was shown that Idyn(0) determined from SANS was in good agreement with the intensity calculated from osmotic swelling pressure measurements.

Thermodynamic and Dynamic Responses to Deforestation in the Maritime Continent: A Modeling Study

Abstract Tropical deforestation can result in substantial changes in local surface energy and water budgets, and thus in atmospheric stability. These effects may in turn yield changes in precipitation. The Maritime Continent (MC) has undergone severe deforestation during the past few decades but it has received less attention than the deforestation in the Amazon and Congo rain forests. In this study, numerical deforestation experiments are conducted with global (i.e., Community Earth System Model) and regional climate models (i.e., Regional Climate Model version 4.6) to investigate precipitation responses to MC deforestation. The results show that the deforestation in the MC region leads to increases in both surface temperature and local precipitation. Atmospheric moisture budget analysis reveals that the enhanced precipitation is associated more with the dynamic component than with the thermodynamic component of the vertical moisture advection term. Further analyses on the vertical profile of moist static energy indicate that the atmospheric instability over the deforested areas is increased as a result of anomalous moistening at approximately 800–850 hPa and anomalous warming extending from the surface to 750 hPa. This instability favors ascending air motions, which enhance low-level moisture convergence. Moreover, the vertical motion increases associated with the MC deforestation are comparable to those generated by La Niña events. These findings offer not only mechanisms to explain the local climatic responses to MC deforestation but also insights into the possible reasons for disagreements among climate models in simulating the precipitation responses.

Characterizing salt permeability in polyamide desalination membranes using electrochemical impedance spectroscopy

Improving the performance of desalination membranes requires better measurements of salt permeability in the polyamide separating layer to elucidate the thermodynamic and kinetic components of membrane permselectivity. In this work, electrochemical impedance spectroscopy (EIS) is introduced as a technique to measure the salt permeability and estimate the salt partition coefficient in thin polyamide films created using molecular layer-by-layer deposition. The impedance of supported polyamide films ranging in thickness from 3.5 nm to 28.5 nm were measured in different electrolyte solutions. Impedance spectra were modeled with equivalent circuits containing resistive and capacitive elements associated with the EIS measurement system as well as characteristic low-frequency parallel resistive and capacitive elements that are associated with the polyamide film. The characteristic polyamide membrane resistance increases with film thickness, decreases with solution concentration, and is an order of magnitude greater for a divalent cationic solution than for a monovalent cationic solution. For each polyamide film, salt permeability is calculated from the membrane resistance, and a salt partition coefficient is estimated. At the highest solution concentration measured, which is representative of brackish water desalination conditions, the calculated salt permeabilities range from Ps = 1.3×10−16 ms−1 to 3.9×10−16 m s−1, and the estimated salt partition coefficients range from Ks = 0.008 to 0.016. These measurements demonstrate that EIS is a powerful tool for studying membrane permselectivity through the measurement of salt permeability in thin polyamide films.

The mechanisms behind changes in the seasonality of global precipitation found in reanalysis products and CMIP5 simulations

As the global atmosphere warms, water vapor concentrations increase with rising temperatures at a rate of 7%/K. Precipitation change is associated with increased moisture convergence, which can be decomposed into thermodynamic and dynamic contributions. Our previous studies involving Coupled Model Intercomparison Project Phase 3 (CMIP3) projections have suggested that seasonal disparity in changes of global precipitation is primarily associated with the thermodynamic contribution. In this study, a vertically integrated atmospheric water budget analysis using multiple reanalysis datasets demonstrated that dynamic changes played a significant role in seasonal precipitation changes during 1979–2008, especially in the global average and ocean average. The thermodynamic component exhibited almost consistent magnitude in the contribution of seasonal precipitation changes during 1979–2008 in both CMIP5_AMIP models and reanalysis datasets, whereas the dynamic component (related to the tendency of ω and water vapor climatology) made a lower or negative contribution in the CMIP5_AMIP models compared with the reanalysis datasets. Strengthened (weakened) ascending and descending motions in the reanalysis datasets (CMIP5_AMIP models), which were indicative of strengthened (weakened) seasonal mean circulation, tended to increase (reduce) precipitation in the wet season and reduce (increase) precipitation in the dry season during the study period. Vertical profiles of the tendency of moist static energy in the mid-to-upper troposphere suggested a trend toward stability in the CMIP5_AMIP models and one toward instability in the reanalysis datasets. Such disagreement in stability might be related to the different warming tendency in the mid-to-upper troposphere over the tropics.

Evidences of felsic volcanism and hydrothermal activities from clays associated with the Palaeoproterozoic Porcellanite Formation of the Vindhyan Supergroup, Central India

Chemico-mineralogical attributes of authigenic clays associated with the altered volcanic tuffs that occur in the Palaeoproterozoic Porcellanite Formation contain evidences of hydrothermal alteration and diagenetic processes in a marine environment. Previous sedimentological and geochemical studies on Porcellanite Formation were restricted to the Chopan area, but, the details related to provenance, nature and source of volcanism archived in these clays have not been ascertained. In order to understand these aspects, present study on these authigenic clays were carried out. Clay minerals represent dominance of illite with subordinate amount of montmorillonite. Moreover, low abundance of kaolinite is also noticed. The illite fibers and plates associated with the kaolinite indicate illitization. The kaolinite to illite transformation is favoured by incorporation of K+ ions, derived from the K-feldspar dissolution and its overgrowth. Major oxide contents of these clays and their ratios when plotted over diagrams marked with standard illite, kaolinite, smectite and chlorite compositional fields show clustering within or close to the illite field. Thermodynamic components calculated for these clays when plotted over AR23+AlSi3O10(OH)2 − R23+Si4O10(OH)2 − AR2+R3+Si4O10(OH)2 ternary diagram, data plots lie within the illite, mixed layer I/S and smectite fields. Binary major oxide data plots between bulk rock and authigenic clay compositions showed felsic affinity. Montmorillonite and illite predominated in the eastern and western marginal areas of the Vindhyan Basin, respectively. However, former resulted from the hydrothermal alteration of volcanic glass associated with the ferruginous breccia and altered tuffs and remnants of the volcanic vents, whereas, later is associated with the tuffaceous beds. Owing to the adsorption, Ba, Rb and Sr is enriched in clays comparing to the bulk rock composition. Low (< 15 ppm) Sc values suggested major contribution from the felsic component. Also, low Rb/Sr and Th/U values revealed moderate insitu weathering. The dominance of K-feldspar alteration and insitu weathering is also evident from clustering of clay data plots in the A-CN-K ternary diagram. Pronounced negative Eu anomaly together with higher LREE/HREE values associated with these clay minerals implied proximity to source and their possible derivation from the silicified felsic tuffs available in the provenance.

Thermodynamic Principles for the Design of Polymers for Drug Formulations.

Polymers play an essential role in drug formulation and production of medical devices, implants, and diagnostics. Following drug discovery, an appropriate formulation is selected to enable drug delivery. This task can be exceedingly challenging owing to the large number of potential delivery methods and formulation and process variables that can interact in complex ways. This evolving solubility challenge has inspired an increasing emphasis on the developability of drug candidates in early discovery as well as various advanced drug solubilization strategies. Among the latter, formulation approaches that lead to prolonged drug supersaturation to maximize the driving force for sustained intestinal absorption of an oral product, or to allow sufficient time for injection after reconstitution of a parenteral lyophile formulation, have attracted increasing interest. Although several kinetic and thermodynamic components are involved in stabilizing amorphous dispersions, it is generally assumed that maximum physical stability, defined in terms of inhibition of drug crystallization, requires that the drug and excipient remain intimately mixed. Phase separation of the drug from its excipient may be the first step that ultimately leads to crystallization. We discuss the role of advanced thermodynamics using two examples: ASD and vitamin E-stabilized ultrahigh-molecular weight polyethylene implants.

Design and off-design optimization procedure for low-temperature geothermal organic Rankine cycles

In this paper, a two-step optimization methodology for the design and off-design optimization of low-temperature (110–150 °C) geothermal organic Rankine cycles (ORCs) is proposed. For the investigated conditions—which are based on the Belgian situation—we have found that the optimal ORC design is obtained for design parameter values for the environment temperature and for the electricity price which are both higher than the respective yearly-averaged values. However, the net present value is negative (−12.62 MEUR) which indicates that the low-temperature (130 °C) geothermal electric power plant is not economically attractive for the investigated case. Nevertheless, and demonstrated by the results of a detailed sensitivity analysis, a low-temperature geothermal power plant might be economically feasible for geological sites with a higher brine temperature or in a country with a more favorable economic situation; e.g., with higher electricity prices (∼70 EUR/MWh). The novelty of our paper is the development of a thermoeconomic design optimization strategy for low-temperature geothermal ORCs, accounting for the off-design behavior already in the design stage. The generic methodology is valid for low-temperature geothermal ORCs (with MW scale power output) and includes detailed thermodynamic and geometric component models, is based on hourly data rather than monthly-averaged data and accounts for economics.