Large Increase In Volume Research Articles

Integration of wellbore pressure measurement and groundwater quality monitoring to enhance detectability of brine and CO2 leakage

Leakage detectability is a key consideration in evaluating the effectiveness of a measurement, monitoring and verification (MMV) plan for a geologic carbon storage (GCS) project. While studies have shown that surface-based, geophysical monitoring methods may be sensitive enough to detect CO2 leakage, these methods are an indirect indicator of leakage. A drawback to relying on direct geochemical monitoring is that by the time a significant leak is confirmed, it may be too late to mitigate or remediate the environmental impacts. In this study, we combine information from geophysical and geochemical monitoring methods to provide an integrated diagnosis of leakage events. The detectability for various monitoring parameters (pH, TDS, alkalinity, Ca, Cl, Na, and pressure) collected from monitoring wells are evaluated by leakage detection probability, using simulated wellbore-leakage/plume-migration events and monitoring scenarios for a hypothetical GCS operation at the Kimberlina site in California, USA. The NUFT code is used to model these events, by coupling wellbore-leakage simulations to 3-dimensional reactive, multi-phase, flow and transport simulations of brine and CO2 leakage-plume migration in aquifers overlying the GCS reservoir. Wellbore leakage in legacy wells located 1.4, 3.4 and 6.8 km from the CO2 injector is evaluated for a range of (1) wellbore bottom-hole pressure and CO2 saturation determined by GCS simulations, (2) regional groundwater gradient in the aquifers, and (3) wellbore permeability. Simulated leakage-induced changes in seven monitoring parameters at different depths are used to calculate the corresponding detection probabilities, based on the background distribution data and selected monitoring-technology detection thresholds. The responses for these monitoring parameters are tested and combined to enhance the overall detectability. The results indicate the leakage signals are more easily detected at shallower depths where buoyant CO2 has migrated and flashed from supercritical to gas phase, causing a large increase in CO2 volume. While the results suggest pH monitoring is more responsive to the simulated leakage events than TDS monitoring at shallower depths, TDS changes may be more readily observed at greater depths. The addition of carbonate alkalinity can confirm CO2 leakage detection and help distinguish CO2 leakage from other contamination sources. Direct pressure change measurements are very sensitive to leakage, but the rapid and broad propagation of the pressure response hinders using such measurements to easily locate the origin of leakage. Combining measurements could greatly improve the confidence of leakage diagnosis. High bottom-hole CO2 saturation, such as that for a leaky well close to the injector (˜1.4 km), high regional groundwater gradient, and high wellbore permeabilities all increase the leakage plume size, and thus the leakage detectability. Our analysis suggests pressure monitoring is a valuable indicator of leakage events at early stages, while pH, TDS and carbonate alkalinity monitoring can directly diagnose leakage impacts by providing more detailed information in the groundwater receptor. Finally, an example Bayesian belief network model is presented for evaluating the effect of risk reduction options in terms of joint monitoring detection probability using the associated simulation scenarios. This framework is demonstrated to inform how pressure and groundwater quality information can be integrated into site MMV and risk management plans.

Volume increase in the dentate gyrus after electroconvulsive therapy in depressed patients as measured with 7T.

Electroconvulsive therapy (ECT) is the most effective treatment for depression, yet its working mechanism remains unclear. In the animal analog of ECT, neurogenesis in the dentate gyrus (DG) of the hippocampus is observed. In humans, volume increase of the hippocampus has been reported, but accurately measuring the volume of subfields is limited with common MRI protocols. If the volume increase of the hippocampus in humans is attributable to neurogenesis, it is expected to be exclusively present in the DG, whereas other processes (angiogenesis, synaptogenesis) also affect other subfields. Therefore, we acquired an optimized MRI scan at 7-tesla field strength allowing sensitive investigation of hippocampal subfields. A further increase in sensitivity of the within-subjects measurements is gained by automatic placement of the field of view. Patients receive two MRI scans: at baseline and after ten bilateral ECT sessions (corresponding to a 5-week interval). Matched controls are also scanned twice, with a similar 5-week interval. A total of 31 participants (23 patients, 8 controls) completed the study. A large and significant increase in DG volume was observed after ECT (M = 75.44 mm3, std error = 9.65, p < 0.001), while other hippocampal subfields were unaffected. We note that possible type II errors may be present due to the small sample size. In controls no changes in volume were found. Furthermore, an increase in DG volume was related to a decrease in depression scores, and baseline DG volume predicted clinical response. These findings suggest that the volume change of the DG is related to the antidepressant properties of ECT, and may reflect neurogenesis.

Muscle metaboreflex-induced central blood volume mobilization in heart failure.

Underperfusion of active skeletal muscle causes metabolites to accumulate and stimulate group III and IV skeletal muscle afferents, which triggers a powerful pressor response termed the muscle metaboreflex. Muscle metaboreflex activation (MMA) during submaximal dynamic exercise in healthy individuals increases arterial pressure mainly via substantial increases in cardiac output (CO). The increases in CO occur via the combination of tachycardia and increased ventricular contractility. Importantly, MMA also elicits substantial central blood volume mobilization, which allows the ventricular responses to sustain the increases in CO. Otherwise preload would fall and the increases in CO could not be maintained. In subjects with systolic heart failure (HF), the ability to increase CO during exercise and MMA is markedly reduced, which has been attributed to impaired ventricular contractility. Whether the ability to maintain preload during MMA in HF is preserved is unknown. Using a conscious chronically instrumented canine model, we observed that MMA in HF is able to raise central blood volume similarly as in normal subjects. Therefore, the loss of the ability to raise CO during MMA in HF is not because of the loss of the ability to mobilize blood volume centrally. NEW & NOTEWORTHY In normal subjects during dynamic exercise muscle metaboreflex activation elicits large increases in cardiac output that occur via increases in heart rate, ventricular contractility, and, importantly, marked central blood volume mobilization that acts to maintain ventricular preload, thereby allowing the changes in cardiac function to maintain the increases in cardiac output. In subjects with heart failure, the ability to raise cardiac output during muscle metaboreflex activation is impaired. We investigated whether this is because of the inability to maintain ventricular preload. We found that this reflex is still able to elicit large increases in central blood volume, and therefore the limited ability to raise cardiac output likely stems from ventricular dysfunction and not the ability to maintain preload.

Changes in Volume and Density Parameters Measured on Computed Tomography Images Following Stereotactic Body Radiation Therapy of Nonspine Bone Metastases.

Introduction:Volumetric and density parameters measured from computed tomography scans were investigated for evaluating treatment response of nonspine bone lesions following stereotactic body radiation therapy.Methods:Twenty-three patients treated with stereotactic body radiation therapy to nonspine bone metastases with pre- and post-treatment radiological follow-up with computed tomography imaging were identified in a retrospective review. An expert radiologist classified 26 lesions by type (lytic, sclerotic) and by response. Two independent radiation oncologists created separate contours of the bone and soft tissue lesion volumes. Density and volume were assessed relative to baseline values.Results:For bone-only lesions, all lesions designated as local control decreased in volume or remained within 20% of baseline volumes. Lytic lesions classified as progressive disease exhibited much larger volume increases. Lytic bone lesions showed indications of remineralization with some exhibiting immediate increases in density (1-6 months) and others decreasing initially then increasing back toward baseline between 7 and 12 months. The majority of sclerotic lesions, all classified as local control, decreased slightly in both volume and density. Lesions with both soft tissue and boney involvement resulted in contradictory results when employing both radiological and size parameters for assessing treatment response. Classification was dominated by changes in soft tissue volume, despite associated volume or density changes in the corresponding boney lesion. In contrast, when soft tissue volume changes were minimal (<20% increase), classification appeared to be related primarily to density changes and not bone volume.Conclusions:Volume and density changes show promise as quantitative parameters for classifying treatment responses of nonspine osseous lesions. Further work is required for clarifying how these metrics can be applied to lesions with both boney and soft tissue components.

Integration of Wellbore Pressure Measurement and Groundwater Quality Monitoring to Enhance Detectability of Brine and CO2 Leakage

Abstract Leakage detectability is a key consideration in evaluating the effectiveness of a measurement, monitoring and verification (MMV) plan for a geologic carbon storage (GCS) project. While studies have shown that surface-based, geophysical monitoring methods may be sensitive enough to detect CO2 leakage, these methods are an indirect indicator of leakage. A drawback to relying on direct geochemical monitoring is that by the time a significant leak is confirmed, it may be too late to mitigate or remediate the environmental impacts. In this study, we combine information from geophysical and geochemical monitoring methods to provide an integrated diagnosis of leakage events. The detectability for various monitoring parameters (pH, TDS, alkalinity, Ca, Cl, Na, and pressure) collected from monitoring wells are evaluated by leakage detection probability, using simulated wellbore-leakage/plume-migration events and monitoring scenarios for a hypothetical GCS operation at the Kimberlina site in California, USA. The NUFT code is used to model these events, by coupling wellbore-leakage simulations to 3-dimensional reactive, multi-phase, flow and transport simulations of brine and CO2 leakage-plume migration in aquifers overlying the GCS reservoir. Wellbore leakage in legacy wells located 1.4, 3.4 and 6.8 km from the CO2 injector is evaluated for a range of (1) wellbore bottom-hole pressure and CO2 saturation determined by GCS simulations, (2) regional groundwater gradient in the aquifers, and (3) wellbore permeability. Simulated leakage-induced changes in seven monitoring parameters at different depths are used to calculate the corresponding detection probabilities, based on the background distribution data and selected monitoring-technology detection thresholds. The responses for these monitoring parameters are tested and combined to enhance the overall detectability. The results indicate the leakage signals are more easily detected at shallower depths where buoyant CO2 has migrated and flashed from supercritical to gas phase, causing a large increase in CO2 volume. While the results suggest pH monitoring is more responsive to the simulated leakage events than TDS monitoring at shallower depths, TDS changes may be more readily observed at greater depths. The addition of carbonate alkalinity can confirm CO2 leakage detection and help distinguish CO2 leakage from other contamination sources. Direct pressure change measurements are very sensitive to leakage, but the rapid and broad propagation of the pressure response hinders using such measurements to easily locate the origin of leakage. Combining measurements could greatly improve the confidence of leakage diagnosis. High bottom-hole CO2 saturation, such as that for a leaky well close to the injector (˜1.4 km), high regional groundwater gradient, and high wellbore permeabilities all increase the leakage plume size, and thus the leakage detectability. Our analysis suggests pressure monitoring is a valuable indicator of leakage events at early stages, while pH, TDS and carbonate alkalinity monitoring can directly diagnose leakage impacts by providing more detailed information in the groundwater receptor. Finally, an example Bayesian belief network model is presented for evaluating the effect of risk reduction options in terms of joint monitoring detection probability using the associated simulation scenarios. This framework is demonstrated to inform how pressure and groundwater quality information can be integrated into site MMV and risk management plans.

Effect of Structure and Chemical Activation on the Adsorption Properties of Green Clay Minerals for the Removal of Cationic Dye

In this study, natural clay minerals with green appearance were treated with sulfuric acid. Mass percentage of acid (wt%), temperature (T), contact time (t) and liquid-to-solid mass ratio (R) are used as the prevailing factors that determine the extent of acid-activation. The values of these factors range from 15–50%, 60–90 °C, 1.5–6 h and 4–7, respectively. The study has focused on the structural changes as well as textural characteristics of the clay. Three activated clay samples were prepared under different treatment conditions. The samples were characterized using X-ray powder diffraction (XRD), fourier transform infrared (FTIR), scanning electron microscope (SEM), chemical analysis and N2 adsorption techniques. Characterization of the treated clay minerals exhibited significant structural changes to a greater extent of acid-activation, from being partially crystalline to being amorphous silica. The surface area and total pore volume of clay increased proportionally with the level of acid treatment. The average pore diameter behaved differently. During the strong acid treatment, a large increase in pore volume and the enlargement of the pore size distribution were observed. This suggests that considerable structural changes and partial destruction may have occurred in this condition. The removal of methylene blue, used as cationic dye, from aqueous solution by the batch adsorption technique on three prepared acid-activated clay samples was studied. The Langmuir model was found to agree well with the experimental data.

Delayed hydride cracking of Zr-2.5%Nb pressure tube material due to partially constrained precipitates

Formation of partially constrained precipitates such as hydride blisters and oxide nodules have been reported on surfaces of Zr-alloy components of pressurised heavy water reactors and is associated with a large increase in volume. Such a change in volume imposes large stresses in the material surrounding the precipitate and may facilitate stable crack growth through delayed hydride cracking. In this work, the stress field of the partially constrained precipitates with different depth and aspect ratio has been computed using a finite element method. The computed stress field is used to predict the region in the matrix in which radial hydride is likely to form and fracture, by taking into consideration grain-size, texture and multi-axial state of stress. For a hypothetical crack just below the precipitate, stress intensity factors are estimated using material properties for both unirradiated and irradiated pressure tube materials. The results are compared with the threshold stress intensity factors required for crack growth due to delayed hydride cracking.

Experimental Investigation of the Pressure of Crystallization of Ca(OH)2: Implications for the Reactive Cracking Process

AbstractMineral hydration and carbonation can produce large solid volume increases, deviatoric stress, and fracture, which in turn can maintain or enhance permeability and reactive surface area. Despite the potential importance of this process, our basic physical understanding of the conditions under which a given reaction will drive fracture (if at all) is relatively limited. Our hydration experiments on CaO under uniaxial loads of 0.1 to 27 MPa show that strain and strain rate are proportional to the square root of time and exhibit negative, power law dependence on uniaxial load, suggesting that (1) fluid transport via capillary flow is rate limiting and (2) decreasing strain rate with increasing confining pressure might be a limiting factor in reaction driven cracking at depth. However, our experiments also demonstrate that crystallization pressure due to hydration exceeds 27 MPa (consistent with a maximum crystallization pressure of 153 MPa for the same reaction, Wolterbeek et al., https://doi.org/10.1007/s11440‐017‐0533‐5). As a result, full hydration can be achieved at crustal depths exceeding 1 km, which is relevant for engineered fracture systems.

A non-reflexive method based on the variability of temperature and bioimpedance in measuring inflammatory hyperalgesia and analgesia in mice

BackgroundPreclinical studies measure withdrawal responses to evoking thermal and mechanical stimuli instead of the more clinically important spontaneous pain. New methodTherefore, we studied the effect of peripheral inflammation induced by intraplantar administration of complete Freund’s adjuvant (CFA) in mice on the variability of temperature and bioimpedance as an index of pain produced by inflammation. To this end, we initially determined mathematical scores based on changes in temperature and bioimpedance (STB) for animals with an inflamed paw and compared these scores with commonly used measures of inflammatory pain. We then pharmacologically validated the tool using dexamethasone. ResultsThe STB analysis resembled the response found in the von Frey Hair (vFH) test. The CFA-induced increase in STB and vFH tests were reversed by intraperitoneal administration of dexamethasone. The correlation between the STB and vFH measurements showed a high correlation coefficient (R2 = 0.911, p < 0.001). Comparison with existing methodOur results also demonstrated that CFA paw injection induced mechanical hyperalgesia in mice and remained virtually unaltered during all time-points tested for 5 days, as measured with vFHs. The administration of CFA into the paw induced a large increase in paw volume that was apparent 1 and 5 days after the injection. The CFA injection resulted in a significant (p < 0.05) decrease in the response latency to the heat stimulus, as evaluated on day 4 post-CFA injection. ConclusionsThe data presented here suggest that STB may provide a novel non-invasive approach for inflammatory pain detection.

Abstract WP345: Pre-Intracerebral Hemorrhage Antiplatelet and Anticoagulant Use and Differences in Hospital Course; A Population-Based Study

Objective: Patients on antiplatelet (AP) or anticoagulant (AC) agents cause more alarm when they develop intracerebral hemorrhage (ICH) compared with non-users. This analysis aimed to quantitatively evaluate the differences in the hospital course of ICH patients based on underlying AP and/or AC use, using a population-based cohort. Methods: Genetic and Environmental Risk Factors for Hemorrhagic Stroke (GERFHS III) was a population-based study of spontaneous ICH among residents of the five-county Greater Cincinnati/Northern Kentucky region between July 2008 and December 2012. Baseline demographics, medications, hospital course, and discharge disposition were collected. Initial and subsequent computed tomography (CT) images of the head were reviewed to assess ICH location, volume, and presence of intraventricular hemorrhage (IVH). Change in ICH volume was calculated when repeat CT image was available. Results: There were 1121 cases of ICH during the study period. A higher proportion of white patients were on AP or AC than other races (56.4% vs. 39.7%, p&lt;.0001). The majority of patients with subsequent imaging experienced an increase in ICH size. Patients taking AC pre-ICH had a larger increase in volume despite more frequent use of pro-thrombotic therapy. There was no difference in IVH incidence based on AP or AC use. Length of stay and surgical hematoma evacuation rates were similar among the groups. Inpatient mortality was higher in AC users (44.4% vs. 21.3%, p&lt;.0001), but was virtually the same for AP users as for non-users. Of 272 pre-ICH AP users, 86 (31.6%) were discharged on AP (8 on dual AP). Of 91 pre-ICH AC users, 11 (12%) were discharged on AC. Conclusion: Pre-ICH AC use was associated with greater ICH volume increase and inpatient death. There was no significant difference in number of IVH, rate of surgical treatment, or length of stay. Inpatient mortality did not differ between AP users and non-users.

Computed tomography study of the fetal development of the dairy cow stomach complex

In the fetal development of animals, critical physiological and anatomical events influence the long-term health and performance of the offspring. To identify the critical growth phases of the fetal bovine stomach, we used computed tomography imaging on 30 German Holstein fetuses to examine the fetal bovine stomach in situ. Computed tomography allows the study of diverse parameters such as the volume of the stomach chambers in situ without the need for sophisticated filling preparation techniques. The absolute volume, relative volume, and monthly volume increase of each stomach chamber were determined. Computed tomography was a reliable method for in situ examination of the fetal bovine stomach complex from the third month of gestation onward. It was able to detect an abnormal position of the abomasum in 2 fetuses. The crown-rump length of the fetuses studied ranged from 9.5 to 89 cm (from 2.2 to 8.3 mo of gestation). Over this timeline, the changes in the relative volumes of the ruminoreticulum and abomasum were inversely related. Until mo 5 of gestation, the relative volume of the ruminoreticulum increased steadily, whereas that of the abomasum decreased. Thereafter, the relative volume of the ruminoreticulum became gradually smaller, and that of the abomasum became larger; by mo 8, the abomasum was larger than the ruminoreticulum. All stomach chambers had large increases in volume over the gestation period and we observed differences in development patterns and volume changes of the individual stomach chambers over this period. The largest monthly volume increase of the stomach complex was between mo 4 and 5 of gestation. In this period, the volume of the ruminoreticulum increased 43.8 times, that of the omasum 38.9 times, and that of the abomasum 30.03 times. Between mo 5 and 6 of gestation, the abomasum had another growth spurt, with a monthly volume increase of 10.4 times. These 2 time points in the gestation period may be critical phases of fetal development that should be considered in the management of pregnant cattle.

Posterior cranial vault distraction osteogenesis in craniofacial surgery: Technical note

Posterior cranial vault distraction is a treatment for intracranial hypertension in certain cases of craniosynostosis and faciocraniosynostosis. It allows the harmonization of the skull back and prevents turricephaly. This study presents the surgical technique. Posterior cranial vault distraction osteogenesis consists of a circular osteotomy of the skull back. Four distractors are placed on the cranial flap without detachment of the dura mater. The distraction is carried out over nearly 1 month with an objective of 20mm. The technique's effectiveness is judged on the correction of the skull back shape and the disappearance of clinical and radiological signs of intracranial hypertension. Posterior cranial vault distraction osteogenesis enables a large increase in cranial volume and a correction of the dysmorphic skull back. This easy surgery and the low rate of complications make this technique a main surgical approach in the management of faciocraniosynostosis.

Effects of melatonin implantation on the fertility potentials of Kivircik and Charollais ewes and rams during the non-breeding season.

This study examined the effect of melatonin implantation during the non-breeding season on the reproductive performance of ewes and the testicular dimensions of rams. In seasonally anestrus Kivircik and Charollais ewes and rams were subjected to melatonin. Estrus response was significantly higher in treated than control ewes of both breeds (p<0.001). The pregnancy rate was significantly lower (p<0.001) in the control than in the treated animals. The twinning rate was significantly lower in melatonin implanted Kivircik than Charollais ewes (p<0.05). The testicular dimensions after 42 days of melatonin treatment increased in both breeds. Scrotal length (SL) increased in Kivircik and Charollais rams (p<0.01). The increase in scrotal circumference (SC) was more marked in the Charollais (P<0.01) than in the Kivircik rams. There was a large increase in testicular volume (TV) in both Kivircik (p<0.01) and Charollais (p<0.001) rams. This study shows that melatonin implants can be applied to induce estrus in ewes approximately four months earlier than breeding season. Melatonin implantation in the non-breeding season significantly increased testicular dimensions in Kivircik and Charollais rams thus increasing their reproductive potential.

Plant cell walls

Plants are able to generate large leaf surfaces that act as two-dimensional solar panels with a minimum investment in building material, thanks to a hydrostatic skeleton. This requires high intracellular pressures (up to 1 MPa), which depend on the presence of strong cell walls. The walls of growing cells (also called primary walls), are remarkably able to reconcile extreme tensile strength (up to 100 MPa) with the extensibility necessary for growth. All walled organisms are confronted with this dilemma - the need to balance strength and extensibility - and bacteria, fungi and plants have evolved independent solutions to cope. In this Primer, we discuss how plant cells have solved this problem, allowing them to support often very large increases in volume and to develop a broad variety of shapes (Figure 1A,B,D). This shape variation reflects the targeted deposition of wall material combined with local variations in cell-wall extensibility, processes that remain incompletely understood. Once the cell has reached its final size, it can lay down secondary wall layers, the composition and architecture of which are optimized to exert specific functions in different cell types (Figure 1E-G). Such functions include: providing mechanical support, for instance, for fibre cells in tree trunks or grass internodes; impermeabilising and strengthening vascular tissue to resist the negative pressure of the transpiration stream; increasing the surface area of the plasma membrane to facilitate solute exchange between cells (Figure 1C); or allowing important elastic deformation, for instance, to support the opening and closing of stomates. Specialized secondary walls, such as those constituting seed mucilage, are stored in a dehydrated form in seedcoat epidermis cells and show rapid swelling upon hydration of the seed. Other walls, in particular in reserve tissues, can accommodate large amounts of storage polysaccharides, which can be easily mobilized as a carbon source. Here we will discuss some general principles underlying wall architecture and wall growth that have emerged from recent studies, as well as future questions for investigation (Box 1).

Investigation of the Order–Disorder Rotator Phase Transition in KSiH3 and RbSiH3

The β–α (order–disorder) transition in the silanides ASiH3 (A = K, Rb) was investigated by multiple techniques, including neutron powder diffraction (NPD, on the corresponding deuterides), Raman spectroscopy, heat capacity (Cp), solid-state 2H NMR spectroscopy, and quasi-elastic neutron scattering (QENS). The crystal structure of α-ASiH3 corresponds to a NaCl-type arrangement of alkali metal ions and randomly oriented, pyramidal, SiH3– moieties. At temperatures below 200 K ASiH3 exist as hydrogen-ordered (β) forms. Upon heating the transition occurs at 279(3) and 300(3) K for RbSiH3 and KSiH3, respectively. The transition is accompanied by a large molar volume increase of about 14%. The Cp(T) behavior is characteristic of a rotator phase transition by increasing anomalously above 120 K and displaying a discontinuous drop at the transition temperature. Pronounced anharmonicity above 200 K, mirroring the breakdown of constraints on SiH3– rotation, is also seen in the evolution of atomic displacement paramet...

Effects of freeze-thaw cycle on engineering properties of loess used as road fills in seasonally frozen ground regions, North China

Compacted loess is widely used as fills of road embankments in loess regions of northern China. Generally, densely-compacted loess can satisfy the requirements of embankment strength and post-construction deformation. I lowever, uneven subsidence, pavement cracks and other related damages can affect the integrity of loess subgrade after several years of operation, and even cause some hazards, especially in North China, where the strong freeze-thaw erosion occurs. In this study, cyclic freeze-thaw tests for both densely and loosely compacted loess samples were performed to determine the variation in engineering properties such as volume, void ratio, collapsible settlement, microstructure, and the related mechanisms were addressed. The experimental results showed that an obvious water migration and redistribution occurred within the samples during freeze-thaw cycles. Ice lenses and fissures could be identified in the upper frozen layers of the samples. After freeze-thaw cycles, the dry densities of the nipper layers of samples changed significantly due to strong freeze-thaw erosion. The dry densities decreased for the dense sample and increased for the loose sample. It can be found that dense samples become loose, while loose samples became dense with the increasing number of freeze-thaw cycles. Their related void ratios changed reversely. Both void ratios tended to fall into a certain range, which verified the concept of a residual void ratio proposed by Viklander. The loosening process of densely compacted samples involves the formation of large pores, volume increase and density reduction as well as the related changes in mechanical properties because freeze-thaw cycles may be important contribution to problems of loess road embankments. Adverse effects of freeze-thaw cycles, therefore, should be taken into account in selecting loess parameters for the stability evaluation of road embankment in seasonally frozen ground regions.

Alimentary canal of fifth instar larvae of &lt;i&gt;Lymantria dispar&lt;/i&gt; (Lepidoptera: Erebidae, Lymatriinae)

Here, the alimentary canal of fifth instar larvae of the gypsy moth (Lymantria dispar) was re-investigated with light microscopy (LM), and for the first time with laser scanning confocalmicroscopy (LSCM) and scanning electronmicroscopy (SEM). We describe morphological characteristics and provide morphometric data. Well-developed dilator muscles and Malpighian bladders suggest a high capacity for food propulsion, excretion, absorption, and detoxification. The epithelium of the alimentary canal of L. dispar is histologically simple and that of the midgut is composed of columnar, goblet, and regenerative cells. Particular arrangement of the intima of crop with a central ventral region recalling a ladder and numerous folds was detected, indicating the capability for a large increase in volume to store food. Numerous spinules were observed on the cuticular intima of pylorus and spinules of a different type were observed on the pyloric valve, and these might assist in propelling the feces.

Research of consumer properties of leather filled with the use of electroactivated water reagent solutions

Consumer properties of the filled macroporous chrome­tanned semi­finished leather obtained by the developed technology using electrochemically activated aqueous solutions of the composition comprising xanthan acrylamide were studied. Sorption­desorption properties of different sections of the filled material during its interaction with water, relaxation and deformation characteristics, differential moisture content on a thermo­gravi­calorie­metric installation, volume yield were determined. It was found that the leather material obtained by the developed technology has higher elastic and plastic strain components by 1.7 and 1.3 times respectively compared with the current technology; porosity, volume yield and hygroscopic ability of obtained samples exceed those of the samples of the experimental technology by 4.5; 19.0; and 9.8–11.3 % respectively. The technology of filling of chrome­tanned leather material from pig skin is implemented by diffusion of the composition ingredients in the anolyte solution at pH 4.2–4.4 with the reduction of surface tension, the formation of mostly hydrogen bonds between the elements of the modified structure of collagen and the filler reagents. The interaction with water results in partial destruction of bonds that are restored after moisture removal. Optimum consumer properties are achieved at a certain ratio of the hydrophilic ability and the differential porosity type of the leather material. The use of the filling composition involving xanthan acrylamide in the anolyte provides effective alignment of porosity in different sections of the semi­finished product due to preferred filling of large pores and increase in the specific volume of smaller pores with the composition. The resulting fine­pored leather material with the split fibrillar structure causes a smaller loss of its area by 0.3 % after moisturizing and drying processes compared with the current technology. The leather material formed using the developed technology due to the complex of consumer properties is recommended for making the insides of shoes – insoles and lining and moisture removal material in the mechanical surface cleaning of products and structures.

Mineral Precipitation Kinetics: Assessing the Effect of Hydrostatic Pressure and Its Implication on the Nucleation Mechanism

Sulfate minerals (barite, anhydrite, and celestite) can be a technological hindrance as a result of scale formation especially for operations where seawater injection is involved. The effect of pH, temperature, and saturation index (SI) on sulfate mineral nucleation and growth are fairly well-known, but the influence of pressure on the nucleation kinetics has attracted no attention. Here we show that nucleation kinetics of barite, anhydrite, and celestite is highly dependent on hydrostatic pressure applied even under constant thermodynamic driving force, that is, at the same supersaturation level. Activation parameters of barite nucleation kinetics were calculated, and measured values are in agreement with literature. The negative activation volume measured suggests that barite nucleation from hydrated Ba2+ and SO42– ions is coupled to an overall volume decrease, albeit a large volume increase due to dehydration is expected. The results indicate that nucleation is not controlled by desolvation of solvated...

Critical role of tumor necrosis factor receptor 1 in the pathogenesis of pulmonary emphysema in mice.

COPD is a major cause of chronic morbidity and mortality throughout the world. Although tumor necrosis factor-α (TNF-α) has a critical role in the development of COPD, the role of different TNF receptors (TNFRs) in pulmonary emphysema has not been resolved. We aimed to clarify the role of TNFRs in the development of pulmonary emphysema. TNF-α transgenic mice, a murine model of COPD in which the mice spontaneously develop emphysema with a large increase in lung volume and pulmonary hypertension, were crossed with either TNFR1-deficient mice or TNFR2-deficient mice. After 6 months, the gross appearance of the lung, lung histology, and pulmonary and cardiac physiology were determined. In addition, the relationship between apoptosis and emphysema was investigated. Pulmonary emphysema-like changes disappeared with deletion of TNFR1. However, slight improvements were attained with deletion of TNFR2. Apoptotic cells in the interstitium of the lung were observed in TNF-α transgenic mice. The apoptotic signals through TNFR1 appear critical for the pathogenesis of pulmonary emphysema. In contrast, the inflammatory process has a less important role for the development of emphysema.