Decrease In Voided Volume Research Articles

State-of-Charge Dependent Change in the Microporous Structure of Graphite Electrodes

Regarding the negative electrode, the most used electrode material in commercially available lithium-ion batteries (LIBs) up to the present day is graphite.1 Upon battery operation, an irreversible volume change in the microporous structure of the graphite electrode is detected. It is associated with the formation of the solid-electrolyte interphase (SEI) within the first cycles and an irreversible thickness increase of the electrode. Consequently, one observes a change in the electrode’s porosity after the initial formation cycles.2,3 Next to irreversible microstructure changes, one observes reversible changes in the microstructure associated with the intercalation of Li-ions into the host structure of the graphite particles upon charging the battery. The electrode particles expand during this process, increasing particle volume by ~13% when fully lithiated.4 In commercial LIBs, electrode materials, separators, and current collectors are tightly packed for a high volumetric energy density. This restricts the thickness expansion of the electrodes.5 Consequently, the graphite particles must expand into the internal pores of the electrodes, resulting in a decrease in the void volume of the porous network. Since the porous electrodes and the separator are filled with the electrolyte and the particle expansion of graphite is more significant than that of the active material in the positive electrode, one observes electrolyte motion in commercial LIBs during charge and discharge. It can be tracked by techniques requiring neutron beam facilities or expensive devices such as X-ray CT instruments.2,6 Recently, Aiken et al. developed a relatively simple apparatus to track the electrolyte motion by monitoring the changing moment of inertia of cylindrical cells during operation and simplifying the approach to study the discussed effect.In this study, we developed a method to track the reversible change of the microporous structure of an artificial graphite (MAGE-5, Hitachi, Japan) with an LP572 electrolyte (1 M LiPF6 in EC:EMC 7:3 w:w with 2 wt% VC, Gotion) during a charge and discharge cycle after formation employing electrochemical impedance spectroscopy (EIS) and operando dilatometry with both cell setups having a 1.5 bar cell compression Since the electrode’s microstructure is connected to the macroscopic properties using the MacMullin number of:NM=τ/ε=RIon·A·κ/dit correlates the porosity , electrodes thickness , ionic pore resistance , area of the electrode , conductivity of the electrolyte , and the tortuosity .8 Thus, we analyzed the change of the ionic pore resistance of graphite electrodes employing EIS in a MAGE//Li half-cell setup with a micro-reference electrode and a free-standing graphite electrode.Due to the particle expansion, we monitor an increase of the ionic pore resistance of up to 40% during charging, i.e., lithiation, of the graphite electrode.Next, we determined the SOC-dependent increase in thickness of the graphite electrode revealing a reversible thickness increase of 3%. Knowing the relation of porosity and tortuosity in a generalized Bruggeman form and using Equation 1 as described above with a constant electrode area and assuming a constant electrolyte conductivity , allowed us to extract the relative SOC-dependent decrease in porosity and void volume of the electrodes. At the end of the charge, both values decreased by approx. 10% and 9%, respectively, confirming the electrolyte repression from the graphite electrode.

Voiding defects in acute radiation cystitis driven by urothelial barrier defect through loss of E-cadherin, ZO-1 and Uroplakin III

Long term-side effects from cancer therapies are a growing health care concern as life expectancy among cancer survivors increases. Damage to the bladder is common in patients treated with radiation therapy for pelvic cancers and can result in radiation (hemorrhagic) cystitis (RC). The disease progression of RC consists of an acute and chronic phase, separated by a symptom-free period. Gaining insight in tissue changes associated with these phases is necessary to develop appropriate interventions. Using a mouse preclinical model, we have previously shown that fibrosis and vascular damage are the predominant pathological features of chronic RC. The goal of this study was to determine the pathological changes during acute RC. We identified that radiation treatment results in a temporary increase in micturition frequency and decrease in void volume 4–8 weeks after irradiation. Histologically, the micturition defect is associated with thinning of the urothelium, loss of urothelial cell–cell adhesion and tight junction proteins and decrease in uroplakin III expression. By 12 weeks, the urothelium had regenerated and micturition patterns were similar to littermate controls. No inflammation or fibrosis were detected in bladder tissues after irradiation. We conclude that functional bladder defects during acute RC are driven primarily by a urothelial defect.

Voiding behavior in awake unrestrained untethered spontaneously hypertensive and Wistar control rats.

The spontaneously hypertensive rat (SHR), a genetic model of high blood pressure, has also been studied as a potential model of overactive bladder. In vivo studies have confirmed the presence of surrogate markers of overactive bladder, including detrusor overactivity, increased urinary frequency, decreased bladder capacity and voided volume (VV), and afferent hypersensitivity to bladder irritation. However, these observations were during awake cystometry using implanted bladder catheters tethered to an infusion pump and artificially filled. We conducted experiments in awake unrestrained untethered age-matched female SHRs and Wistar rats to quantify naïve consumption and voiding behavior and the effect of capsaicin desensitization on consumption and voiding behavior. Food and water consumption, body weight, voiding frequency, and VV were recorded. Rats were placed in metabolism cages for 24 h, up to twice a week, from 17 to 37 wk of age. Compared with Wistar rats, SHRs exhibited decrease in VV and did not exhibit diurnal variation in VV between light and dark periods, suggesting that SHRs may have bladder hypersensitivity. Furthermore, SHRs may also have smaller bladder capacities, as they consumed less water, voided less volume (regardless of light cycle), and had equal urinary frequencies compared with age-matched Wistar rats. We detected no change in SHR voiding behavior following capsaicin desensitization, which was in contrast to a prior awake in vivo cystometry study describing increased VV and micturition interval in SHRs and suggests that C-fiber activity may not contribute to bladder hypersensitivity in SHRs.NEW & NOTEWORTHY We characterized the long-term (20 wk) voiding, defecation, and consumption behavior of age-matched spontaneously hypertensive and Wistar rats without the influence of anesthesia or catheters. Spontaneously hypertensive rats exhibited bladder hypersensitiviy that persisted for the 20-wk duration and was unaffected by capsacin desensitization.

Analysis of permeability reduction in drainage asphalt mixtures due to decrease in void volume

Pavements with a wearing course of drainage asphalt mixtures have been used in regions with high rainfall due to their ability to remove stormwater from the surface and increase the tire-pavement adhesion. However, over time, due to traffic flow together with dirt carried by surface runoff, the voids are reduced and become clogged. This work presents a laboratory study for the evaluation of the reduction in the void volume and permeability of drainage asphalt mixtures through the action of traffic and clogging. The reduction in the void volume was simulated in two different ways. Firstly, cylindrical specimens produced in a SUPERPAVE gyratory compactor were compacted using 50 gyrations as a reference and to simulate the action of traffic other specimens were compacted considering 75, 100, 150 and 200 gyrations. In order to evaluate permeability and voids content reduction due to permanent deformation along the time, slabs were conditioned applying 1,000, 3,000, 5,000, 10,000, 20,000 and 30,000 cycles in the traffic simulator. After that, the plates were core drilled to cylindrical specimens to perform tests. Specimens without conditioning were used as a reference. The permeability was then measured using clean water and surface runoff. From different levels of traffic simulation, the permeability from 1.84 mm/s (0 cycles) to 1.55 mm/s (30,000 cycles) while the void volume decreased from 23.50% (0 cycles) to 22.24% (30,000 cycles). Intervention was considered to be required when the reduction in the connected void volume reached 12%. In this case, intervention should be conducted annually for an average of void volume of 24.5% and within seven months for an average of void volume of 20.6%. Thus, in order to maintain the draining properties of the pavement surface, intervention such as cleaning and suction of pores should be carried out in the first year after the opening of the roadway to traffic.

Assessing Aerosol Performance of a Dry Powder Carrier Formulation with Increasing Doses Using a Novel Inhaler.

This study aims to investigate the implications of loaded formulation mass on aerosol performance using a reservoir novel dry powder inhaler containing a custom dosing cup to deliver carrier-based formulation to the lungs. A 3D printed dosing cup with volume size of 133.04mm3 was manufactured to allow for the progressive loading of different carrier formulation masses of 1% beclomethasone dipropionate BDP (w/w) formulation (10 to 60mg, with increments of 10mg), in a novel customizable DPI device. Scanning electron micrographs were used to investigate BDP detachment from carrier particles post-aerosolisation and particle deposition on the USP induction port. The subsequent aerosol performance analysis was performed using the next generation impactor (NGI). Incrementally increasing the loading mass to 60mg led to decreases in BDP detachment from carrier particles, resulting in significant decreases in aerosol performance. Increases in loading dose mass led to progressively decreased detachment of BDP from the carrier and the overall aerosol performance in comparison to the initial mass of 10mg. These results are likely to be due to a decrease in void volume within the dosing cup with increased loading mass leading to altered airflow, decreased impaction forces and the possibility of a significant quantity of large carrier particles introducing a 'sweeping' effect on the inhaler inner surface. This study has shown that despite the decreased BDP detachment from the carrier and decreased aerosol performance, the dose delivered to the lung still increased due to the higher loaded dose.

Influence of Organic Pigment Blending on Surface and Optical Properties of Coated Paper

The effects of several factors including organic pigment blending and calending conditions on the surface and optical properties of coated paper were investigated. When clay and calcium carbonate are blended in the ratio of 7 to 3, highest smoothness and relative sediment volume were obtained. When organic pigments were added to the mixture of clay and calcium carbonate, the relative sediment volume did not changed significantly. However, when organic pigments were added to calcium carbonate, sheet gloss and smoothness were improved, and showed the better results than that obtained from the mixture of organic pigment and clay. When organic pigment is blended with clay, the particles of organic pigment are buried in the packing structure of coating layer. However, the particle shape of calcium carbonate is quite different from that of clay, and the aspect ratio of calcium carbonate is similar to that of organic pigment. Thus organic pigment particles are not buried and improved effectively the physical characteristics of coating layer. When the hollow sphere pigment was blended, opacity and sheet gloss were improved significantly. Even though the coating color applied was reduced, the similar level of opacity was maintained. Also, if particle size and void volume are increased, gloss is improved, because coating layer is easily transformed in calendering. Therefore, even though lower pressure was applied during calendering, the smoothness of surface of coating layer was improved, and the decrease of void volume in coating layer was reduced, and the quality of coated sheet can be improved.

Long-lasting breaches in the bladder epithelium lead to storage dysfunction with increase in bladder PGE2 levels in the rat

Increase in bladder mucosal permeability can be reproduced by intravesical administration of protamine sulfate (PS); however, the influence of PS once administered into the bladder disappears within several days. We developed a chronic animal model of urothelial injury using PS. Insertion of a polyethylene catheter through the bladder dome was performed in female Wistar rats. The other end of the catheter was connected to an osmotic pump for continuous delivery of PS or vehicle for 2 wk. Urinary frequency (UF) and voided volume (VV) were measured in the metabolic cage. The fifth group of rats received a high dose of PS (10 mg/ml) for 2 wk and were followed for a further 2 wk without PS. The sixth group received a high dose of PS for 2 wk and loxoprofen (0.1 mg.kg(-1).day(-1)) for 4 wk. UF was increased, and VV was reduced in rats treated with a high dose of PS but not changed in rats treated with a vehicle or a low dose of PS (1 mg/ml). UF was further increased in the fifth group, while unchanged in the sixth group. Histological sections in rats treated with a high dose of PS demonstrated a loss of the upper layer of urothelial cells and an increased number of mast cells. PGE2 level in the bladder was significantly elevated in the fifth group. These results indicate that chronic urotherial injury leads to an increase in UF and a decrease in VV. Increased PGE2 level in the bladder is likely to be associated with long-lasting storage dysfunction.

LONGITUDINAL CHANGES IN POST-VOID RESIDUAL AND VOIDED VOLUME AMONG COMMUNITY DWELLING MEN

We describe the natural history of post-void residual (PVR) and voided volume (VV) in men. A random sample of community dwelling men (529 men 40 to 79 years old) were followed with a sonographic PVR and VV every 2 years for up to 12 years (median 5 examinations). Men were censored at the time of treatment for a prostate condition. The median annual change (slope) for PVR was 2.2% (p=0.03) and for VV was -2.1% (p <0.0001). There was considerable variability in PVR slopes (25th percentile -11%, 75th percentile 18%). A rapid increase in PVR slope (greater than 80th percentile) was more likely in men with a baseline American Urological Association Symptom Index greater than 7 (age adjusted odds ratio [OR]1.6, 95% CI 1.0 to 2.5). There was less variability in VV slopes (25th percentile -8.0%, 75th percentile 3.1%). A rapid decrease in VV slope (less than 20th percentile) was more likely in men with baseline age 70 to 79 years than 40 to 49 years (OR 3.9, 95% CI 2.1 to 7.2) and in men with a baseline PVR greater than 50 ml (age adjusted OR 2.1, 95% CI 1.2 to 3.6). Although it is highly variable, there is progressive bladder dysfunction in community dwelling men as they age. In addition, signs and symptoms attributed to benign prostatic hyperplasia were modest predictors of the development of bladder dysfunction. A baseline increased PVR predicted a rapid decrease in VV, consistent with a bladder outlet obstruction contributing to the development of detrusor overactivity and decreased bladder compliance.

Water corrosion behavior of densified glass. II. Borate glasses

Densified sodium borate glasses with the compositions of xNa 2O·(100− x)B 2O 3 ( x = 10, 15, 20, 25, 30) were prepared by applying hydrostatic pressures of 2.5, 3.5 and 4.5 GPa at temperatures near the glass transition temperatures. The water corrosion behavior was investigated by a weight loss method. For all compositions, both untreated and densified glasses, a linear time-dependent dissolution behavior and a decrease of dissolution rate were observed. This change depended on glass composition, and was relatively small for 25Na 2O·75B 2O 3 glass. It is assumed that the dissolution process is controlled by the hydrolysis reaction of borate network. The densification-induced changes in the dissolution rates are attributed to both a decrease of void volume and a change in hydrolysis reactivity.

The Effect of Two-dimensional Compressive Stress on the Dissolution Rate of Glass in Water

The dissolution behavior of silicate glasses was studied as a function of compressive stress and time. The two-dimensional compressive stress on glass surface was introduced by utilizing the difference of thermal expansion coefficients between glass and ceramic substrate. The release rates of Na+ ions from these glasses into distilled water were determined by using atomic absorption analysis. As a result, the release rates of Na+ ions increased along with an increase of compressive stress in both diffusion and reaction stage, that is contrary to the general concept that compressive stress reduces the diffusion rate because of a decrease in void volume. In order to explain this behavior, the new hydrolysis mechanism under compressive stress was suggested. FTIR measurements were also carried out to support this mechanism.

Coke formation in zeolite ZSM-5

The coke contents and sorption capacities of three ZSM-5 zeolites with different Al Si ratios were followed during methanol conversion until the zeolites were completely deactivated. For two of the zeolites the volume of coke exceeded the concomitant decrease in void volume, so that some coke must have been sited on the external surfaces of the zeolite crystals. An estimate was made of the ratio of external to internal coke for these zeolites. For the third zeolite the assumption that there was some external coke implies that there was also some topological blocking of parts of the channel system by coke. The presence of internal coke in the third zeolite was deduced by selective removal of coke by oxidation in an oxygen plasma and was confirmed by X-ray diffraction.

On void collapse in viscous solids

On the basis of an approximate method, the collapse of an isolated spherical void in an incompressible power-law viscous material is investigated. Results are found for the decrease in void volume as a function of remote axisymmetric stress state, remote strain, and time.

Effect of electron-irradiation on void formation in helium-pre-injected aluminium films

Abstract The effect of 200 kv electron-irradiation on evaporated aluminium films pre-injected with 35 kev helium ions has been studied. With a fluence of 1 × 1015 ions/cm2 of helium, the damage produced consisted of voids 30–40 A in diameter and dislocation loops 200 A in diameter. Such damage was observed to be enhanced by in-situ electron-irradiation at room temperature (≃ 0.3 Tm ) with a flux of 1 × 1019 electrons/cm2-sec. The enhancement was in the form of increased void number density and void volume in addition ‘to increased interstitial dislocation loop density and loop area. This effect appeared to be temperature-dependent, since a decrease in void volume with a smaller increase in interstitial dislocation loop area was observed on electron-irradiation at 100°C (0°4 Tm ). The annealing of helium-pre-injected films, prior to electron-irradiation, at 100°C resulted in a large increase in void volume accompanied by a slight decrease in dislocation loop number density and loop area although loop size ...

Measurement of Free Fission-Gas Pressure in Operating UO2-Filled Fuel Rods

A differential-type pressure transducer suitable for use in a fast-neutron environment at elevated temperatures has been developed. The sensitivity of this device is approximately 0.25 lb/in.2 with the ability to withstand an unbalance pressure of over 1500 lb/in.2 from either direction. A number of stainless-steel-clad, UO2-filled fuel rods equipped with these transducers have been irradiated in the Vallecitos Boiling Water Reactor to exposures up to roughly 4000 MWd/t peak. These experiments have shown that fission-gas release is negligible from UO2 operated below the recrystallization temperature. For operation at higher temperatures, observed fission-gas pressures were in qualitative agreement with measured void volume and quantity of free gas found in post-irradiation examination. The decrease in void volume during operation has been calculated for a fuel rod and the calculated value used to estimate a mean fuel temperature.