Density Measurements Research Articles

Preparation and characterization of strontium-doped bismuth borate glasses

Employing the melt quenching method, new bismuth borate glass compositions denoted as (40+x)Bi2O3–(60-x-y)B2O3–ySrO, with x and y ranging between 0 to 20 mol%, were synthesized. The X-ray Diffraction analyses confirmed the amorphous nature of all glass samples, indicating the absence of long-range order typically seen in crystalline materials. Concurrently, the Fourier-transform Infrared Spectroscopy examinations unveiled the existence of fundamental structural units within the glasses, including BO3 and BO4 trigonal and tetrahedral units, as well as BiO3 and BiO6 polyhedra, suggesting a complex network structure. Differential Thermal Analysis (DTA) and dilatometry assessed the glasses' thermal properties. DTA demonstrated the glasses' high thermal stability, with a stability value of up to 106°C, noting that stability improves with more SrO. Dilatometry analyses revealed these glasses exhibit a high thermal expansion coefficient, ranging from 8.69 to 10.7 ppm/°C, alongside relatively low glass transition temperatures between 362 and 432°C and dilatometric softening temperatures spanning from 380 to 447°C. Density measurements were conducted, followed by molar volume and oxygen packing density calculations, to glean further insights into the samples. Compared to other heavy-metal oxide glasses, the glasses examined in this study exhibited notably high-density values, ranging between 6.279 and 7.476 g/cm3 .

Accuracy of Volumetric Bone Mineral Density Measurement in Weight Bearing, Cone Beam Computed Tomography

Background: Weight bearing computed tomography (WBCT) utilizes cone beam CT technology to provide assessments of lower limb joint structures while they are functionally loaded. Grey-scale values indicative of X-ray attenuation that are output from cone beam CT are challenging to calibrate, and their use for bone mineral density (BMD) measurement remains debatable. To determine whether WBCT can be reliably used for cortical and trabecular BMD assessment, we sought to establish the accuracy of BMD measurements at the knee using modern WBCT by comparing them to measurements from conventional CT.Methods: A hydroxyapatite phantom with three inserts of varying densities was used to systematically quantify signal uniformity and BMD accuracy across the acquisition volume. We evaluated BMD in vivo (n = 5, female) using synchronous and asynchronous calibration techniques in WBCT and CT. To account for variation in attenuation along the height (z-axis) of acquisition volumes, we tested a height-dependent calibration approach for both WBCT and CT images.Results: Phantom BMD measurement error in WBCT was as high as 15.3% and consistently larger than CT (up to 5.6%). Phantom BMD measures made under synchronous conditions in WBCT improved measurement accuracy by up to 3% but introduced more variability in measured BMD. We found strong correlations (R = 0.96) as well as wide limits of agreement (-324 mgHA/cm3 to 183 mgHA/cm3) from Bland-Altman analysis between WBCT and CT measures in vivo that were not improved by height-dependent calibration.Conclusion: Whilst BMD accuracy from WBCT was found to be dependent on apparent density, accuracy was independent of the calibration technique (synchronous or asynchronous) and the location of the measurement site within the field of view. Overall, we found strong correlations between BMD measures from WBCT and CT and in vivo measures to be more accurate in trabecular bone regions. Importantly, WBCT can be used to distinguish between anatomically relevant differences in BMD, however future work is necessary to determine the repeatability and sensitivity of BMD measures in WBCT.

Risk Factors for Ten-Year Risk of Osteoporosis in Type 2 DM Patients Attending Tikur Anbessa Specialized Hospital Diabetic Center Cross-sectional Study

<i>Background</i>: Type 2 diabetes mellitus (T2DM) is a major contributing factor to osteoporotic fractures via different mechanisms. This study assessed the ten-year risk of osteoporosis and associated factors for osteoporotic fractures in T2DM patients. <i>Methods</i>: Data from 175 type diabetes mellites (T2DM) patients over 40 years attending a diabetes clinic at Tikur Anbessa Specialized Hospital (TASH) were collected. Demographic information, diabetic complications, blood sugar levels, and other medical illnesses were collected by a structured questionnaire and from an electronic medical record system. The 10-year fracture risk assessment (FRAX) tool was used without bone mineral density (BMD) measurement. multivariate logistic regression was used to analyze factors associated with fragility fractures. <i>Results</i>: Half the participants were female, with a median age of 60. Most were married, well-educated, and urban residents. The median duration of diabetes was 11 years. The median FRAX score indicated a moderate 10-year risk of hip fracture (≥3%) and a high risk of major osteoporotic fracture (≥20%). Overall, 30.9% of patients had a high 10-year risk of osteoporotic fracture. The majority (78.3%) had macrovascular complications, with neuropathy, retinopathy, and nephropathy being the common ones. Higher FBS, higher HbA1c, and the presence of macrovascular complications were significantly associated with a higher risk of fractures. <i>Conclusion</i>: This study found a high prevalence (30.9%) of a 10-year risk of osteoporotic fractures in T2 DM patients. Poor glycemic control (higher HbA1c and FBS) and the presence of macrovascular complications were significantly associated with an increased 10-year osteoporotic fracture risk.

Influence of pressure and powder characteristics on the properties and microstructure of Colmonoy-5 alloy sintered by spark plasma sintering

This study investigates the microstructure and final properties of Colmonoy-5, a nickel-based hardfacing alloy, consolidated via spark plasma sintering (SPS) as an alternative to traditional welding deposition on stainless steel substrates. Two batches of Colmonoy-5 alloy powders with different particle sizes used for sample processing. Sintering occurred at 900 °C under pressures of either 50 MPa or 60 MPa for 15 min. The evaluation of the sintered samples included density measurement through Archimedes' method, morphology assessment via confocal microscopy, phase composition analysis by X-ray diffraction (XRD), microstructural examination using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), and hardness testing by Vickers method. Findings indicate that SPS is an effective technique for producing Colmonoy-5, achieving satisfactory densification. The study also reveals that the initial morphology of the precursor powders can influence the size of phases precipitated within the nickel matrix. Sintering pressure of 50 MPa seems to be the most effective in processing Colmonoy-5 via SPS.

Straightforward microwave-assisted synthesis of ultrasmall gold nanoparticles acnhored on reduced graphene oxide for enhanced antibacterial application

Graphene derivative materials, such as graphene oxide (GO) and reduced graphene oxide (rGO), have garnered significant attention from scientists for over two decades due to their distinctive characteristics and versatile applications across various fields, particularly in biomedical applications. Incorporating gold nanoparticles (AuNPs) into rGO sheets as rGO-Au nanocomposites further enhances its performance in biomedical applications. This study presents a rapid and efficient method for synthesizing ultrasmall AuNPs anchored on reduced graphene oxide (rGO-Au) using microwave irradiation and ascorbic acid. The optimum microwave treatment was 4 min, ensuring the highest GO reduction degree. Structural characterization by TEM reveals a distinctive architecture with ultrasmall AuNPs (average size of 2.2 nm) distributed on the rGO sheets. Interestingly, while the synthesized rGO-Au did not exhibit any antibacterial activities against both Escherichia coli and Staphylococcus aureus in disk diffusion assays, it demonstrated bacteriostatic effect at remarkably low concentrations when assessed by optical density measurement. The effective concentration of rGO-Au to inhibit E. coli growth was determined to be 2.5 ppm, while for S. aureus, it was 5 ppm, resulting in growth inhibition of 53.1% and 50.0%, respectively. These findings provide a straightforward synthesis route for rGO-Au nanocomposites and underscore the importance of AuNPs’ size and quantity in modulating antibacterial properties.

Prototyping and characterisation of 316L stainless steel parts and lattice structures printed via metal fused filament fabrication

PurposeThis study aims to deepen the knowledge concerning the metal fused filament fabrication technology through an analysis of the printing parameters of a commercial 316L stainless steel filament and their influence on the porosity and mechanical properties of the printed parts. It also investigates the feasibility of manufacturing complex geometries, including strut-and-node and triply periodic minimal surface lattices.Design/methodology/approachA three-step experimental campaign was carried out. Firstly, the printing parameters were evaluated by analysing the green parts: porosity and density measurements were used to define the best printing profile. Then, the microstructure and porosity of the sintered parts were investigated using light optical and scanning electron microscopy, while their mechanical properties were obtained through tensile tests. Finally, manufacturability limits were explored with reference samples and cellular structures having different topologies.FindingsThe choice of printing parameters drastically influences the porosity of green parts. A printing profile which enables reaching a relative density above 99% has been identified. However, voids characterise the sintered components in parallel planes at the interfaces between layers, which inevitably affect their mechanical properties. Lattice structures and complex geometries can be effectively printed, debinded, and sintered if properly dimensioned to fulfil printing constraints.Originality/valueThis study provides an extensive analysis of the printing parameters for the 316L filament used and an in-depth investigation of the potential of the metal fused filament fabrication technology in printing lightweight structures.

Novel technique for the ultra-sensitive detection of hazardous contaminants using an innovative sensor integrated with a bioreactor

This study introduces an evaluation methodology tailored for bioreactors, with the aim of assessing the stress experienced by algae due to harmful contaminants released from antifouling (AF) paints. We present an online monitoring system equipped with an ultra-sensitive sensor that conducts non-invasive measurements of algal culture's optical density and physiological stage through chlorophyll fluorescence signals. By coupling the ultra-sensitive sensor with flash-induced chlorophyll fluorescence, we examined the dynamic fluorescence changes in the green microalga Chlamydomonas reinhardtii when exposed to biocides. Over a 24-h observation period, increasing concentrations of biocides led to a decrease in photosynthetic activity. Notably, a substantial reduction in the maximum quantum yield of primary photochemistry (FV/FM) was observed within the first hour of exposure. Subsequently, we detected a partial recovery in FV/FM; however, this recovery remained 50% lower than that of the controls. Integrating the advanced submersible sensor with fluorescence decay kinetics offered a comprehensive perspective on the dynamic alterations in algal cells under the exposure to biocides released from antifouling coatings. The analysis of fluorescence relaxation kinetics revealed a significant shortening of the fast and middle phases, along with an increase in the duration of the slow phase, for the coating with the highest levels of biocides. Combining automated culturing and measuring methods, this approach has demonstrated its effectiveness as an ultrasensitive and non-invasive tool for monitoring the physiology of photosynthetic cultures. This is particularly valuable in the context of studying microalgae and their early responses to various environmental conditions, as well as the potential to develop an AF system with minimal harm to the environment.

Additive manufacturing of porous ceramic structures by indirect powder bed fusion with laser beam using a novel polyamide/alumina-based feedstock

Porous alumina structures were developed by indirect Powder Bed Fusion with Laser Beam (PBF-LB), employing a novel feedstock (composite granules) based on alumina (Al2O3), bio-renewable polyamide 612 (PA612), and micron-sized graphite (MG) using a commercial PBF-LB machine that operates with a low-power visible light diode laser. Regular and slightly rounded composite granules were prepared via the thermally induced phase separation (TIPS) process in dimethyl sulfoxide (DMSO) using 0.05 vol% of PA612, 40/60 vol% of Al2O3/PA612 and 6.25 wt% of MG, and then characterized via density measurements, Hausner's ratio, SEM-EDS, particle size distribution, Raman spectroscopy, DSC, and TGA. Experimental conditions to be used in the PBF-LB process were determined in order to obtain high-quality green porous structures with a controlled geometry. After the heating treatments, sintered components with good structural integrity, a high open porosity associated with interconnected pores in the struts, and a ceramic matrix with microsized-equiaxial grains were obtained. The evaluation of the mechanical properties was performed by diametral compression testing. In order to improve these properties, a vacuum infiltration process involving a low-concentration alumina-ethanol suspension was used on pre-sintered discs. As a consequence of the infiltration process, the discs showed improved mechanical properties after sintering without the porosity having been significantly affected.

Exploring Potential Applications of α and β Polymorphs of Bi2O3 Nanoparticles

AbstractIn this investigation, we successfully synthesized bismuth oxide (Bi2O3) nanoparticles (NPs) via simple combustion method using Artocarpous heterophyllus (Jackfruit) extract as fuel. Both α and β polymorphs of bismuth oxide NPs was prepared using same Artocarpous heterophyllus fuel but there is a variation in the addition of fuel in the range of 1 mL–6 mL. The prepared NPs were characterized by utilizing spectroscopic techniques. The photocatalytic efficiencies were found to be 84 %, 93 % for both α, β forms respectively. Methylene blue dye exhibits effective degradation for β‐phase compared to α‐phase. Furthermore, Electrochemical impedance spectroscopy and sensing (CV) activities were performed. The bismuth oxide modified electrodes exhibits better sensing activity towards dopamine, ascorbic acid, lead nitrate, and results obtained from EIS data revealed the super capacitor characteristics of Bi2O3 nanoparticles. This extensive investigation assessed the effectiveness of Aspergillus Niger‐fighting drugs, as well as the antibacterial effects of synthesized nanoparticles on Staphylococcus Aureus and Escherichia Coli. Measurements of optical density were used to establish the MIC values for antifungals. The protein 4XUY has a strong binding affinity of −6.4 Kcal/mol, with four important hydrogen bond interactions (LYS51, HIS84, ASN131, and GLU238) revealed by molecular docking research. These results expand our knowledge of the therapeutic uses of bismuth oxide nanoparticles by highlighting their potential as effective antibacterial agents and by providing insightful information about how they work against pathogenic microorganisms.

Association of mammographic breast density measurements and hormone receptor status of breast cancer.

Breast cancer is the most frequent cancer in women, with significant mortality. Mammography is a routine investigation for breast disease. A known risk factor for breast cancer is increased breast density. Here, we tried to observe if mammographic density also affects the hormone receptor status of breast cancer, which will help in the understanding of the biological mechanisms of breast cancer development. Suspected breast cancer patients at Lok Nayak Hospital, Delhi, underwent mammography in the Department of Radiodiagnosis. The density of breast contralateral to the mass was assessed using Hologic Quantra software version 2.1.1 [Area Breast Density(ABD)]. The hormone receptor status of all the tumours was recorded on histopathology. Of these, 100 confirmed cases were included in the study. ER-positive, PR-positive, and HER2-positive tumours were seen in 41%, 33%, and 34% patients, respectively. Regarding ER receptor status, the mean ABD for positive and negative tumours was 27% and 23%, respectively, p-value = 0.01, showing significant relation between them. Mean ABD for HER2-positive and -negative tumours was 25% and 24%, respectively, p-value = 0.75. Mean ABD for PR-positive and PR-negative tumours was 23% and 25%, respectively, p-value = 0.42 (not significant). We found that ER-positive tumours were common in dense breasts, which was statistically significant. However, this was not true for PR and HER2 receptor status. Limited studies have been done to study MD using computerised software and its effect on hormone receptor status, with conflicting results. Further, large, multicentric studies can be useful in understanding the mechanism and providing better treatment for breast cancer patients.

Enhancing Antimicrobial Performance of Gauze via Modification by Ag-Loaded Polydopamine Submicron Particles.

Silver nanoparticles (AgNPs) are known for their antibacterial properties and their ability to promote wound healing. By incorporating silver nanoparticles into medical gauze, the resulting composite material shows promise as an advanced wound dressing. However, clinical applications are hindered by challenges related to the stability of silver nanoparticle loading on the gauze as nanoparticle leaching can compromise antibacterial efficacy. In this study, silver nanoparticles were immobilized onto polydopamine (PDA) submicron particles, which were then used to modify medical gauze. Energy dispersive spectroscopy (EDS) was employed to analyze the elemental distribution on the modified gauze, confirming successful surface modification. The antibacterial properties of the modified gauze were assessed using a laser scanning confocal microscope (CLSM). The results demonstrated a significant reduction in the adhesion rates of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) by 99.1% and 63%, respectively, on the PDA-Ag-modified gauze. Optical density (OD) measurements at 590 nm indicated that the modified gauze effectively inhibited biofilm formation, underscoring its potent antimicrobial capabilities. Further antibacterial efficacy was evaluated by diluting and plating co-cultured bacterial solutions with the modified dressing, followed by 24 h incubation and colony counting. The gauze exhibited an antibacterial efficiency of 99.99% against E. coli and 99.8% against S. aureus. Additionally, cell compatibility tests, involving the co-culture of PDA-Ag composites with human cells, demonstrated excellent biocompatibility. These findings suggest that PDA-Ag-modified medical gauze holds significant potential for the treatment of infected wounds, offering a promising solution to improve wound care through enhanced antimicrobial activity and biocompatibility.

Mammographic density assessment: comparison of radiologists, automated volumetric measurement, and artificial intelligence-based computer-assisted diagnosis.

Artificial intelligence-based computer-assisted diagnosis (AI-CAD) is increasingly used for mammographic exams, and its role in mammographic density assessment should be evaluated. To assess the inter-modality agreement between radiologists, automated volumetric density measurement program (Volpara), and AI-CAD system in breast density categorization using the Breast Imaging-Reporting and Data System (BI-RADS) density categories. A retrospective review was conducted on 1015 screening digital mammograms that were performed in Asian female patients (mean age = 56 years ± 10 years) in our health examination center between December 2022 and January 2023. Four radiologists with two different levels of experience (expert and general radiologists) performed density assessments. Agreement between the radiologists, Volpara, and AI-CAD (Lunit INSIGHT MMG) was evaluated using weighted kappa statistics and matched rates. Inter-reader agreement between expert and general radiologists was substantial (k = 0.65) with a matched rate of 72.8%. The agreement was substantial between expert or general radiologists and Volpara (k = 0.64-0.67) with a matched rate of 72.0% but moderate between expert or general radiologists and AI-CAD (k = 0.45-0.58) with matched rates of 56.7%-67.0%. The agreement between Volpara and AI-CAD was moderate (k = 0.53) with a matched rate of 60.8%. The agreement in breast density categorization between radiologists and automated volumetric density measurement program (Volpara) was higher than the agreement between radiologists and AI-CAD (Lunit INSIGHT MMG).

Effects of In2O3 doping on the microstructure and electrical properties of ZnO–V2O5–Nb2O5 varistor ceramics

To understand the effects of In2O3 on the microstructure, grain size dispersion, density and nonlinear electrical characteristics, ZnO–V2O5–Nb2O5 varistor ceramics with 0.02, 0.05 and 0.1 mol.% In2O3 were fabricated via sintering at 950–975 °C for 1 h. The sintered samples were evaluated by x-ray diffraction, scanning electron microscopy, density measurements and electrical measurements through a voltage source meter. In2O3 addition improves relative density to ≥99 % and acts as an efficient grain growth inhibitor, resulting in a narrower grain dispersion and finer ZnO grains due to the formation of In–V–O intergranular phases. The breakdown potential (E1mA) increases sharply to 7.49 ± 0.3 kV/cm (from 1.66 ± 0.1 kV/cm) as a result of grain size reduction to 2.1 ± 0.1 μm (from 3.89 ± 0.2 μm) with In concentration of 0.1 mol.% (from 0.02 mol.%). Doping of In2O3 improves the nonlinear exponent and reduces the leakage current density as a direct consequence of enhanced Schottky barrier height.

Are High-Σ1 Massive Blue Spiral Galaxies Rejuvenated Systems?

Quiescent galaxies generally possess denser cores than star-forming galaxies with similar mass. As a measurement of the core density, the central stellar mass surface density within a radius of 1 kpc (Σ1) was thus suggested to be closely related to galaxy quenching. Massive star-forming galaxies with high Σ1 do not fit into this picture. To understand the origin of such galaxies, we compare the spatially resolved stellar population and star formation properties of massive (>1010.5 M ⊙) blue spiral galaxies with high and low Σ1, divided by Σ1 = 109.4 M ⊙ kpc−2, based on the final release of MaNGA integral field unit data. We find that both high-Σ1 and low-Σ1 blue spirals show large diversities in stellar population and star formation properties. Despite the diversities, high-Σ1 blue spirals are statistically different from the low-Σ1 ones. Specifically, the radial profiles of the luminosity-weighted age and Mgb/〈Fe〉 show that high-Σ1 blue spirals consist of a larger fraction of galaxies with younger and less α-element-enhanced centers than their low-Σ1 counterparts, ∼55% versus ∼30%. The galaxies with younger centers mostly have higher central specific star formation rates, which still follow the spaxel-based star formation main-sequence relation. Examinations of the Hα velocity field and the optical structures suggest that galactic bars or galaxy interactions should be responsible for the rejuvenation of these galaxies. The remaining ∼45% of high-Σ1 blue spirals are consistent with the inside-out growth scenario.

Simultaneous measurement of surface velocity and plasma density with interferometric velocimetry.

The apparent velocity measured by an interferometric surface velocimeter is a function of both the surface velocity and the time derivative of the refractive index along the measurement path. We employed this dual sensitivity to simultaneously measure km/s surface velocities and 1018cm-3 average plasma densities with combined VISAR (velocity interferometer system for any reflector) and PDV (photonic Doppler velocimetry) measurements in experiments performed on the Z Pulsed Power Facility. We detail the governing equations, associated assumptions, and analysis specifics and show that the surface velocity can be extracted without knowledge of the specific plasma density profile.

Super-Resolution Ultrasound Imaging for Monitoring the Therapeutic Efficacy of a Vascular Disrupting Agent in an Animal Model of Breast Cancer.

Evaluate the use of super-resolution ultrasound (SRUS) imaging for the early detection of tumor response to treatment using a vascular-disrupting agent (VDA). A population of 28 female nude athymic mice (Charles River Laboratories) were implanted with human breast cancer cells (MDA-MB-231, ATCC) in the mammary fat pad and allowed to grow. Ultrasound imaging was performed using a Vevo 3100 scanner (FUJIFILM VisualSonics Inc) equipped with the MX250 linear array transducer immediately before and after receiving bolus injections of a microbubble (MB) contrast agent (Definity, Lantheus Medical Imaging) via the tail vein. Following baseline ultrasound imaging, VDA drug (combretastatin A4 phosphate, CA4P, Sigma Aldrich) or control saline was injected via the placed catheter. After 4 or 24 hours, repeat ultrasound imaging along the same tumor cross-section occurred. Direct intratumoral pressure measurements were obtained using a calibrated sensor. All raw ultrasound data were saved for offline processing and SRUS image reconstruction using custom MATLAB software (MathWorks Inc). From a region encompassing the tumor space and the entire postprocessed ultrasound image sequence, time MB count (TMC) curves were generated in addition to traditional SRUS maps reflecting MB enumeration at each pixel location. Peak enhancement (PE) and wash-in rate (WIR) were extracted from these TMC curves. At termination, intratumoral microvessel density (MVD) was quantified using tomato lectin labeling of patent blood vessels. SRUS images exhibited a clear difference between control and treated tumors. While there was no difference in any group parameters at baseline (0 hour, P > .09), both SRUS-derived PE and WIR measurements in tumors treated with VDA exhibited significant decreases by 4 (P = .03 and P = .05, respectively) and 24 hours (P = .02 and P = .01, respectively), but not in control group tumors (P > .22). Similarly, SRUS derived microvascular maps were not different at baseline (P = .81), but measures of vessel density were lower in treated tumors at both 4 and 24 hours (P < .04). An inverse relationship between intratumoral pressure and both PE and WIR parameters were found in control tumors (R2 > .09, P < .03). SRUS imaging is a new modality for assessing tumor response to treatment using a VDA.

Side specific differences of Hounsfield-Units in the osteoporotic lumbar spine.

Gold standard for determining bone density as a surrogate parameter of bone quality is measurement of bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA), most commonly performed on the lumbar spine (L1-L4). Computed tomography (CT) data are often available for surgical planning prior to spine procedures, but currently this information is not standardized for bone quality assessment. Besides, measuring the Hounsfield-Units (HU) is also of great importance in the context of biomechanical studies. This in vitro study aims in comparing BMD from DXA and HU based on diagnostic CT scans. In addition, methods are presented to quantify local density variations within bones. One hundred and seventy-six vertebrae (L1-L4) from 44 body donors (age 84.0±8.7 years) were studied. DXA measurements were obtained on the complete vertebrae to determine BMD, as well as axial CT scans with a slice thickness of 1 mm. Using Mimics Innovation Suite image processing software (Materialise NV, Leuven, Belgium), two volumes (whole vertebra vs. spongious bone) were formed for each vertebra, which in turn were divided in their left and right sides. From these total of six volumes, the respective mean HU was determined. HU of the whole vertebra and just spongious HU were compared with the BMD of the corresponding vertebrae. Side specific differences were calculated as relative values. Whole bone and spongious HU correlated significantly (P>0.001; α=0.01) with BMD. A positive linear correlation was found, which was more pronounced for whole bone HU (R=0.72) than for spongious HU (R=0.62). When comparing the left and right sides within each vertebra, the HU was found to be 10% larger on average on one side compared to the opposite side. In some cases, the difference of left and right spongious bone can be up to 170%. There is a tendency for the side comparison to be larger for the spongious HU than for the whole vertebra. Determination of HU from clinical CT scans is an important tool for assessing bone quality, primarily by including the cortical portion in the calculation of HU. Unlike BMD, HU can be used to distinguish precisely between individual regions. Some of the very large side-specific gradients of the HU indicate an enormous application potential for preoperative patient-specific planning.

Study of Temporal Dynamics of Urban Heat Island Surface in Padang West Sumatra, Indonesia

Padang as the capital of the province, is a strategic area and also the center of the economy. Annual population growth affects changes in land use from vegetated land to built-up areas. An increase in barren land will trigger an increase in temperature. SUHI is a temperature phenomenon that occurs on the surface resulting from the increase in temperature. SUHI can be observed through surface temperature data or Land Surface Temperature. This study aims to identify changes in land surface temperature that are affected by changes in land use in the form of building density conditions. In analyzing this using Landsat 7 ETM+ imagery in 2001, 2006, 2011, 2016, and 2020. The building density measurement method LST transformations to measure surface temperature and helps the Surface Urban Heat Island phenomenon. The results of the analysis showed that there was an increase in the building density of the city of Padang over a period of 20 years. This phenomenon affects the surface temperature, indicating that the surface temperature has increased by around 0.47°C. The highest temperature from 2001-2020 occurred in 2016, with the highest temperature of 36°C.

Thermal protection of steel using various ceramic-like fireproofing coatings systems: Comparative study

A comparative study on three types of fireproofing coatings (namely, cementitious, sodium silicate, and epoxy) was made to determine their effectiveness in protecting steel structures. The effects of these coatings on the external protection of steel were structurally, thermally, and mechanically studied. The prepared cementitious coatings endured the heat until 1200 °C for 1 h showing dimensions stability without deformation nor cracking during firing. Both crushing strength (CS) and bulk density measurements decreased from 69 to 18 kg/cm2 and from 1.62 to 1.00 g/cm3 'respectively' with increasing both perlite and vermiculite percentages. Six of the prepared 48 sodium silicate and epoxy coatings succeeded in bearing heat until 900 °C for 3.5 h sustaining the steel substrates' temperature below 60 °C following the Underwriters Laboratory-94 (UL-94) standard. This protective effect was due to the formation of a hard glassy phase on the steel surface isolating it from the heat by the action of the applied constituents. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) thermograms for these succeeded samples revealed that they gave a high residual weight ranging from 63 to 88% when tested from room temperature up to 900 °C. Performing the scanning electron microscopy (SEM) test revealed that physical blending between both the binder and additives (other coating ingredients’) has occurred. The results concluded that the used ingredients, which have low prices, compared to the imported ones, and are locally available, are recommended for the fire protection of steel.

Fundamental role of nonlocal orders in 1D extended Bose-Hubbard model.

Nonlocal order parameters capture the presence of correlated fluctuations between specific degrees of freedom, in otherwise disordered quantum matter. Here, we provide a further example of their fundamental role, deriving the ground state phase diagram of the filling one extended Bose-Hubbard model, exclusively in terms of their ordering. By means of a density matrix renormalization group numerical analysis, we show that in addition to the (even) parity order characteristic of the Mott insulating phase and the string order nonvanishing in the Haldane insulator, the recently proposed odd parity order completes the picture, becoming nonvanishing at the transition from the normal superfluid to the paired superfluid phase. The above three nonlocal parameters capture all the distinct phases, including the density wave phase, in which the local order is seen as the simultaneous presence of correlated fluctuations in different channels. They provide a unique tool for the experimental observation of the full phase diagram of strongly correlated quantum matter, by means of local density measurements.