Abstract 1122‐000128: Imaging Follow‐Up in Carotid Webs: Is There Vascular Remodeling?

Introduction : Carotid web (CaW) is a shelf‐like fibrotic projection at the carotid bulb and constitutes an underrecognized cause of ischemic stroke. Atherosclerotic lesions are known to have dynamic remodeling with time however, little is known regarding the evolution of CaW over time. We aimed to better understand if CaW is a static or dynamic entity on delayed vascular imaging. Methods : This was a retrospective analysis of the CaW database at our comprehensive stroke center, including patients diagnosed with CaW between September 2014 through June 2021. Patients who had at least two good quality CT angiograms (CTAs) that were at least 6 months apart were included (CTAs with CaW and superimposed thrombus were excluded). CaW were quantified with 3‐D measurements using Horos software. This was done via volumetric analysis of free‐hand delineated CaW borders on thin cuts of axial CTA (Figure 1 Panel A). NASCET criteria was used to evaluate the degree of stenosis. Results : Sixteen CaW in 13 patients were identified and included. The median imaging follow‐up window was 16 months (IQR 12–22, range 6–29). Median patient age was 45.5 years‐old, 69% were women, 25% had hypertension, 38% hyperlipidemia, 25% diabetes mellitus, 0% atrial fibrillation, and 13% active smokers. 75% of the included CaW were symptomatic while 25% were asymptomatic. Median volume of CaW on initial CTA (8.52 mm3 [IQR 3.7‐13], range 2.2‐30.4) was comparable to median volume of CaW on most recent CTA (8.47 mm3 [IQR 4.0‐12.8], range 2.3‐29.4; p = <0.001 (Figure 1 Panel B). The CaW volumetric measurement correlation between the initial and most recent CTA was near perfect (rs = ‐0.99, p = <0.001). The median change in measured volume of CaW between first and last CTA was ‐0.19 mm3 [IQR ‐0.6‐0.4], range ‐1‐0.8. Median degree of stenosis was 8.1% [IQR 4.5‐17.1], range 0.4‐31.2. The duration of follow‐up imaging was not correlated with the change in CaW volume (Kendall tau‐b[τb] = ‐0.17, p = 0.93). The initial CaW volume was not found to be correlated to the degree of stenosis (τb = ‐0.08, p = 0.65). Conclusions : The volume of the CaW was not found to change over time, reinforcing the idea that this is a relatively static lesion. The CaW volume was not found to correlate with the degree of stenosis caused by it. Further longitudinal studies with longer follow‐up intervals are warranted.

Qualimetric assessment of metrological characteristics of household gas meters during periodic verification

Informative parameters for statistical estimation of operational error of SAMGAS, METRIX, PREMAGAS household gas meters (HGM) are formulated. These are the values of the measured volume during the verification period of operation and the experimentally determined error of the meter during operation at three normalized flow rates: minimum, maximum and 20% of the maximum. Six ranges of variation of the HGM error at the minimum flow rate were selected to form statistical samples of meters. According to the proposed algorithm, the change in the weighted average HGM error for three normalized flow rates from the measured volume is quantified, taking into account the number of HGMs and their error ranges. It is proposed to apply the concept of generalized weighted average error of HGM, which reflects the operational error of HGMs during their operation in the entire range of consumption when measuring gas volumes up to 60 thousand cubic meters.

Oil Losses Problem in Oil and Gas Industries

Oil losses is a problem that often arises in oil and gas industries either in onshore or offshore area. There is a loss discrepancy between total quantities from shippers and measurement in the storage tanks; the total sending volume is lower than the measured volume in the mixing tank in a gathering station; this is known as oil losses. When this occurs, an agreement to determine a fair share of the losses must be made. There are two categories of oil losses, they are individual and group losses. Individual loss occurs when oil from one shipper has not been mixed yet with other oils. This includes emulsion and evaporative losses. Group loss occurs during mixing oils in the same storage tank or pipeline. Furthermore, by knowing the causes of oil losses, a way to minimize oil losses can be determined.

Fluid intelligence and naturalistic task impairments after focal brain lesions

Classical executive tasks, such as Wisconsin card-sorting and verbal fluency, are widely used as tests of frontal lobe control functions. Since the pioneering work of Shallice and Burgess (1991), it has been known that complex, naturalistic tasks can capture deficits that are missed in these classical tests. Matching this finding, deficits in several classical tasks are predicted by loss of fluid intelligence, linked to damage in a specific cortical 'multiple-demand' (MD) network, while deficits in a more naturalistic task are not. To expand on these previous results, we examined the effect of focal brain lesions on three new tests - a modification of the previously-used Hotel task, a new test of task switching after extended delays, and a test of decision-making in imagined real-life scenarios. As potential predictors of impairment we measured volume of damage to a priori MD and default mode (DMN) networks, as well as cortical damage outside these networks. Deficits in the three new tasks were substantial, but were not explained by loss of fluid intelligence, or by volume of damage to either MD or DMN networks. Instead, deficits were associated with diverse lesions, and not strongly correlated with one another. The results confirm that naturalistic tasks capture cognitive deficits beyond those measured by fluid intelligence. We suggest, however, that these deficits may not arise from specific control operations required by complex behaviour. Instead, like everyday activities, complex tasks combine a rich variety of interacting cognitive components, bringing many opportunities for processing to be disturbed.

Tympanometry and computed tomography measurement of middle ear volumes in patients with unilateral chronic otitis media

<p class="abstract"><strong>Background: </strong>Tympanometry and computed tomography (CT) measurement of middle ear volume in patients with unilateral chronic otitis media.</p><p class="abstract"><strong>Methods: </strong>The prospective study was conducted on 50 patients of diagnosed unilateral chronic otitis media showing clinical symptoms which affect quality of life. Patients who were fulfilling inclusion criteria after screening were selected for study. We studied patients who had a unilateral tympanic membrane (TM) perforation and a normal TM in the contralateral ear which act as control group to estimate the ME volume in the lesioned ear. Further we have compared pre and postoperative middle ear volume (measured by CT and tympanometry) in control &amp; diseased ear to correlate middle ear volume results obtained by CT and Tympanometry.</p><p class="abstract"><strong>Results: </strong>The mean value of MEV measured by tympanometry and CT were (1.343±0.580) and (1.106±0.380) respectively (Figure 1). Volume measurement by tympanometry is higher as compared to volume measured by CT in lesioned ear, hence tympanometry measured volume in diseased ear were higher that measured by CT which is closer to normal values in both normal and Diseased ears. Also hearing shows improvement in diseased ear after surgery due to restoration of middle ear volume closer to normal.</p><p class="abstract"><strong>Conclusions:</strong> It was concluded in our study that CT is more reliable investigation for middle ear volume measurement as compared to Tympanometry in diseased as well as normal ears.</p>

Effect of filter extraction solvents on the measurement of the oxidative potential of airborne PM2.5

Solvent extraction of PM2.5 samples collected on the filter is a preliminary step for assessing the PM2.5 oxidative potential (OP) using cell-free assays, as the dithiothreitol (DTT) and the ascorbic acid (AA) assays. In this study, we evaluated the effect of the solvent choice by extracting ambient PM2.5 samples with different solvents: methanol, as organic solvent, and two aqueous buffers, i.e., phosphate buffer (PB) and Gamble’s solution (G), as a lung fluid surrogate solution. Both the measured volume-based OPVDTT and OPVAA responses varied for the different extraction methods, since methanol extraction generated the lowest values and phosphate buffer the highest. Although all the tested solvents produced intercorrelated OPVDTT values, the phosphate buffer resulted the most useful for OPDTT assessment, as it provided the most sensible measure (nearly double values) compared with other extractions. The association of the measured OPV values with PM chemical composition suggested that oxidative properties of the investigated PM2.5 samples depend on both transition metals and quinones, as also supported by additional experimental measurements on standard solutions of redox-active species.

Titrimetric Analysis of Chloride Concentration in Beers using Synthetic Mercury(II) Compound

The monothiocyanato-mercuric(II) nitrate [Hg(SCN)NO3] reagent has been prepared synthetically in an aqueous medium and subjected for studies of titrimetric analysis of chloride concentration in beers. In this studies, a measured volume of beer sample was added into known and an excess amount of Hg(SCN)NO3 reagent and the surplus Hg(SCN)NO3 was determined by back titration against standard potassium thiocyanate (KSCN) solution using ferric nitrate [Fe(NO3)3] indicator. The chloride ion and Hg(SCN)NO3 were found to be reacting in the 1:1 stoichiometric ratio. The amount of chloride in beer was determined with the amount of Hg(SCN)NO3 utilized in the titration reaction. The presence of organic and inorganic materials had no effect on the titrimetric assay of chloride concentration in beers as proved by the chloride recovery experiment. The statistical analysis of results showed average standard deviation of 0.01034 and average relative error 1.12%, which indicates the accuracy of the procedure.

Poética de lo transitorio: una revisión de Inert Gas Series/Helium, Neon, Argon, Krypton, Xenon/ From a Measured Volume to Indefinite Expansion, de Robert Barry (1969)

Este estudio busca indagar la poética de la transitoriedad desplegada de Inert Gas Series/Helium, Neon, Argon, Krypton, Xenon/From a Measured Volume to Indefinite Expansion (Serie de gases inertes / Helio, neón, argón, criptón, xenón / De un volumen medido a una expansión indefinida), de Robert Barry (1969). Esta obra consistió en la liberación de gases desde sus contenedores a la atmósfera en diversos lugares de California, la cual fue anunciada por medio de un cartel blanco en el que se publicaron los datos de una dirección de correos y un número de teléfono, al que respondía una máquina contestadora con la grabación de su descripción. Con lo anterior, se pone en obra una dimensión temporal que se debate entre la fugacidad del gesto performático y la infinitud de lo que implica conceptualmente, que problematiza la inmaterialidad y que desplaza los valores plásticos a valores implícitos en la idea de obra como un ejercicio conceptual. Pero ¿qué implica la desmaterialización total del soporte de obra?, ¿qué es lo que intenta mostrar Serie de gases inertes mediante la alusión al tiempo? y ¿qué importancia tiene el arte, en tanto conceptual, para articular una idea de magnitud en la obra? Esta investigación busca responder a tales cuestionamientos desde la premisa de que la obra de Barry, como propuesta inmaterial, temporal y conceptual, logra presentar una serie de paradojas en torno al arte que articulan una poética de la transitoriedad, la cual es puesta a prueba mediante la comparación con otros ejemplos de obra (Rachel Whiteread, Oscar Muñoz y Olafur Eliasson). Finalmente, la poética de la transitoriedad exhibe la imposibilidad de retener el transcurso temporal mediante dispositivos plásticos que se proponen como un flujo, esto es, representan el cambio espacial/material en el tiempo.

Quantifying the volume increase and chemical exchange during serpentinization

Quantifying the concurrent changes in rock volume and fluid composition during serpentinization remains a major challenge in assessing its physicochemical effects during continental rifting, seafloor spreading, and subduction. Here we conducted a series of 11 hydrothermal laboratory experiments where cylindrical cores of natural dunite, harzburgite, and pyroxenite were reacted with an aqueous solution at 300 °C and 35 MPa for up to 18 months. Using three-dimensional microcomputed tomography and thermogravimetry, we show that rock volume systematically increased with time and extent of reaction, leading to a volume increase of 44% (±8%) in altered rock domains after 10–18 months of serpentinization. The volume expansion was accompanied by Mg-Ca exchange between fluid and rock, while Fe and Si were largely conserved. We find that the protolith composition (olivine/orthopyroxene ratio) plays a significant role in controlling the fluid chemistry and the proportions of hydrous secondary minerals during serpentinization. Agreement between alteration mineralogy, composition of reacting fluids, and measured volume changes suggests that serpentinization under static conditions is a volume-increasing process in spite of demonstrable mass transfer. Volume expansion implies an increased water carrying capacity and buoyancy force of serpentinite per unit mass of protolith, while Mg-Ca exchange during serpentinization may affect the Mg/Ca ratio of seawater on Earth and possibly other ocean worlds.

Comparison of Porosity Evaluation Methods Using the Example of Dissimilar Metal Joints

Welded metal porosity significantly influences the mechanical properties of dissimilar metal joints. In this study, the comparison of porosity evaluation methods was held using the sample of welded-brazed zinc coated steel and Al-Mg-alloy plates joint. Relative porosity was measured through cross-sections’ images area analysis, as well as it was evaluated through 3D-fitting of spotted on these images pores. Area and size of pores was measured, volume and distribution were evaluated. It was found that relative porosity values estimated by 2D and 3D methods are equal.