Density Grade Research Articles

Rotating significance of parabolical movement antique with an appearance on isothermal vertical plate by MHD

The proper explicit testing with a rotation impact is wavering parabolical stream antique. It is an incomprehensive, electrical forceful liquid. Isothermal vertical plates are done standardized accelerated abundant lack magneto hydrodynamic described. T’W and the centre equal close to the vessel have been higher near C’w. The value by a plate degree and density grade closer to the plate are step-up constantly. This Logical methodology of the issue addressed the limit state with temperature. Fixations are t. Dimension - less equivalence was assimilated by using the Laplace approach. Velocity outline, climate, absorption shape is developed alternate bodily models corresponding deep (or) mass Grashof value, Schmidt value, prandtl value, rotational boundary, period. The velocity will venture rising appraisal deep Grashof rate. It is furthermore tried that the speed ventures up with diminishing rotational parameters.

Group Behavior Pattern Recognition Algorithm Based on Spatio-Temporal Graph Convolutional Networks

With the rapid growth of population, more diverse crowd activities, and the rapid development of socialization process, group scenes are becoming more common, so the demand for modeling, analyzing, and understanding group behavior data in video is increasing. Compared with the previous work on video content analysis, factors such as the increasing number of people in the group video and the more complex scene make the analysis of group behavior in video face great challenges. Therefore, a group behavior pattern recognition algorithm based on spatio-temporal graph convolutional network is proposed in this paper, aiming at group density analysis and group behavior recognition in the video. A crowd detection and location method based on density map regression-guided classification was designed. Finally, a crowd behavior analysis method based on density grade division was designed to complete crowd density analysis and video group behavior detection. In addition, this paper also proposes to extract spatio-temporal features of crowd posture and density by using the double-flow spatio-temporal map network model, so as to effectively capture the differentiated movement information among different groups. Experimental results on public datasets show that the proposed method has high accuracy and can effectively predict group behavior.

Effect of Tantalum on Coltan in Cassiterite Using Mathematical Modeling Approach with Respect to Gibbs Energy

The objectives of this study were to evaluate the effect of tantalum on COLTAN in Cassiterite using mathematical modeling approach and how it controls the strength, cell size, magnetization, and density (grade), as well as electrical conductivity of COLTAN in Cassiterite. The effectiveness of COLTAN in Cassiterite in Extractive Industry depends on the ratio of tantalum to niobium in the solid solution during crystallization of magma with respect to Gibbs free energy and can be mathematically expressed as Z[X n-x Y x ]O 6 as n ranges from 0 to 5 where x depends on’ n’. Mathematically, cassiterite consists of small ion lithophile elements, large ionic charge, with intermediate to greater ionic potential and these elements are partitioned along the aqueous phase, if both the aqueous phase and silicate phase coexist together during crystallization of magma. These trace elements include tin, iron; niobium, tantalum, and zircon are incompatible trace elements because of their inability to achieve a charge balance with silicate structure (SiO 4 ) in the silicate magma phase. These elements do not exist as free ions in the magma but form complexes with oxygen in the magma during crystallization. Methodologically, 20kg of cassiterite was crushed and pulverized in the laboratory mill machine for an hour, and was taken and sized by sieving into number of size fractions using the automatic sieve shaker for 15 minutes, after processing using high intensity magnetic separator and with the help of ordinary hand magnet of about 0.01Tesla, relative density measure, triaxial testing machine to measure the strength, the relationship between columbite and tantalite can be mathematically established using a COLTAN model. Findings have shown that, with increasing amount of tantalum atom on COLTAN, the COLTAN becomes more tantalized, and both are strong when subjected to shear modulus ,electrical conductivity of COLATN also increases with increasing tantalum, but with its greater density, small cell size because of lanthanide contraction than the niobium, increasing the number of tantalum on COLTAN in cassiterite increases the quality of COLTAN in cassiterite, therefore we haveniobate type cassiterite, tantalized type cassiterite and coltan type cassiterite. In conclusion, the presence or absence of tantalum on COLTAN determines their genetic rock origin, in which the amount of tantalum on COLTAN increased from alkali rock with ∆ G ≥ 0, e.g., nephelinesyenite to more silicic, with ∆ G > 0, e.g., granite pegmatite which gives the account that cassiterite rich in niobium is less dense than the cassiterite rich in tantalum.After comparative analyses between columbite and tantalite in cassiterite, concise valuable substantive empirical novel model was developed and can be employed to study COLTAN in cassiterite. This concise empirical novel model was, “COLTAN model designed with the aid of: Matrix equation, Oxidation and the Tantalization process, and can be recommended to study the effect of tantalum on COLTAN and the application can improve mineral processing in extractive Industry.

Relationship Between Ultrasound Features and Ki-67 Labeling Index of Soft Tissue Sarcoma.

ObjectivesTo explore the relationship between ultrasound (US) features and Ki-67 labeling index (LI) of soft tissue sarcoma (STS).MethodsForty-six patients with 47 STS lesions, between September 2014 and April 2020, were enrolled in the study. Point-biserial correlation analysis and Spearman’s correlation analysis were utilized to examining the relationship between the US features and the Ki-67 LI of STS. The differences of US features between high and low Ki-67 proliferation groups were statistically analyzed by independent t test, Wilcoxon rank-sum test, and Fisher’s exact test. The optimal cut-off points of US features revealing significant differences were estimated by the maximum Youden index.ResultsA moderate correlation between the vascular density grade and the Ki-67 LI (ρ = 0.409, P = 0.004) was found in this study. In addition, other ultrasound features were irrelevant to the Ki-67 LI. The cut-off for differentiating low- and high-proliferation groups was grade II according to the best Youden index. The area under receiver operating characteristic (ROC) curve was 0.74 (p = 0.011) with a sensitivity of 60.6% and specificity of 78.6%.ConclusionsOnly the vascular density grade of STS had a weak positive correlation with Ki-67 LI, and might be capable of predicting the proliferation of STS. Other ultrasonographic features of STS such as shape and tumor margin have no correlation with Ki-67 LI.

Retinitis pigmentosa-associated anterior subcapsular cataract: morphological features and visual performance.

To investigate the morphological features and surgical outcomes of retinitis pigmentosa (RP)-associated anterior subcapsular cataract (ASC). Consecutive RP-associated ASC cases were reviewed, and one hundred patients (171 eyes) were included. Anterior segment photographed images by slit-lamp microscope were reviewed. Best-corrected visual acuity (BCVA) was recorded. The cases were classified according to preoperative best BCVA, the area (central, midperipheral and peripheral) and the density (Grade 1, vacuolar/bubble-like; Grade 2, plaque-like/translucent; and Grade 3, fibrotic/opaque) of ASC; subgroup analysis of surgical outcomes was then performed. The mean age was 52.1 ± 13.7years, and the 41-50-year group had the best BCVA. 13.5% of eyes had BCVA better than 20/63, 30.4% were between 20/400 and 20/63, and 56.1% were worse than 20/400. The percentage of ASCs in the central, midperipheral and peripheral areas was 55.0%, 37.4% and 7.6%, respectively. Postoperative BCVA was improved in the central and midperipheral groups (P < 0.001) but was not in the peripheral group (P = 0.07). The percentage of ASCs in density of Grade 1, 2 and 3 was 11.1%, 38.6% and 50.3%, respectively. Grade 2 and 3 achieved improved postoperative BCVA (P < 0.001), but Grade 1 did not (P = 0.693). Mostly, ASC is located at the center of the pupillary area and affected the residual vision of RP patients. The patients benefited from cataract removal except for those with ASC extended to peripheral area. Surgery was also recommended for RP with ASC developed to be plaque-like and even fibrotic.

Quantitative breast density analysis to predict interval and node-positive cancers in pursuit of improved screening protocols: a case\u2013control study

BackgroundThis study investigates whether quantitative breast density (BD) serves as an imaging biomarker for more intensive breast cancer screening by predicting interval, and node-positive cancers.MethodsThis case–control study of 1204 women aged 47–73 includes 599 cancer cases (302 screen-detected, 297 interval; 239 node-positive, 360 node-negative) and 605 controls. Automated BD software calculated fibroglandular volume (FGV), volumetric breast density (VBD) and density grade (DG). A radiologist assessed BD using a visual analogue scale (VAS) from 0 to 100. Logistic regression and area under the receiver operating characteristic curves (AUC) determined whether BD could predict mode of detection (screen-detected or interval); node-negative cancers; node-positive cancers, and all cancers vs. controls.ResultsFGV, VBD, VAS, and DG all discriminated interval cancers (all p < 0.01) from controls. Only FGV-quartile discriminated screen-detected cancers (p < 0.01). Based on AUC, FGV discriminated all cancer types better than VBD or VAS. FGV showed a significantly greater discrimination of interval cancers, AUC = 0.65, than of screen-detected cancers, AUC = 0.61 (p < 0.01) as did VBD (0.63 and 0.53, respectively, p < 0.001).ConclusionFGV, VBD, VAS and DG discriminate interval cancers from controls, reflecting some masking risk. Only FGV discriminates screen-detected cancers perhaps adding a unique component of breast cancer risk.

Observation analysis of wind climate in China for 1971–2017 under the demand of wind energy evaluation and utilization

To meet the requirement of the wind energy resource assessment and utilization, the statistical characteristics of wind climate in the China mainland were analyzed in this study by using observation wind dataset for 1971–2017 from the China Meteorological Administration (CMA). A series of key factors closely related to wind power development were analyzed, systematically including the spatial and temporal characteristic of wind speed, the distribution of wind speed at different density grades, the density of the cumulative distribution, strong wind days and weak wind days. The characteristics of wind patterns in different regions are also compares. Results indicate that: (1) the regions with the highest wind speed in China centrally locate in Northwest China, North China and Northeast China with the highest wind speed occurs in spring. The annual variation of wind speed in northern China is bimodal while in southern China it is unimodal. (2) The wind speed probability density distribution shows a significant spatial–temporal difference. The wind speed probability distribution is the most concentrated in spring for almost all regions. For each season, the concentrated and stable wind speed occurs in Xinjiang region in spring. While it appears in the region from Northwest China to the northern part of North China for summer and autumn, and in the southern part of North China and Central China for winter. In the case of equal cumulative probability, the highest wind speed locates in Northeast China and the lowest in Sichuan Basin. (3) For 1971–2017, the wind speed in all regions of China showed a decreasing trend on the whole. But this trend slowed down since 1990s. It is​ worth noting that the wind speed in some regions even increased since 2000. (4) The numbers of strong wind day have been decreasing in all regions, but the numbers of weak wind day demonstrate an evolutionary feature of a growth followed by decrease. In most regions, the numbers of weak wind day reached the maximum in the vicinity of 2000 and then decreased rapidly.

Symptoms presentation and aggressiveness pattern of prostate cancer in a Moroccan population

Around the world, prostate cancer is one of the leading types of cancer in men. Indeed, according to the most recent reports, approximately 1.27 (7.1%) million new cases were diagnosed with an estimated 358,989 (3.8%) deaths. Prostate cancer manifests in a varied incidence according to the ethnic-geographic origin of patients. In Morocco, it is a public health issue regarding its frequency and severity, being the second most common male cancer with 3990 (15.8%) new cases recorded in 2018. This work aims at depicting the pattern of prostate cancer presentation in the Moroccan population for the first time, in regard to some clinical and pathological features along with aggressiveness nature in patients followed up in Mohammed V military hospital of Rabat which is a referral center. In this retrospective record-based study, the epidemiological, clinical, and histo-biological characteristics of 104 prostate cancer cases, at the time of diagnosis were assessed, such as age, prostate-specific antigen (PSA) level, Gleason grade, symptomatic pattern. Data analysis was done by the software SPSS version 23 using the statistical test two-tailed Pearson Qui-square test and two-tailed independent t-test. The results show that the mean age at diagnosis is 68 years. The mean PSA level, prostate volume and PSAd (PSA density) levels were 70.08 ng/ml, 61 grams and 1.66 ng/ml/gm respectively. Half of the patients had a PSA level of less than 10 ng/ml and only 21.2% were accidentally discovered during systematic screening. Symptomatic patients were significantly associated with age ( P = 0.04) and with digital rectal examination (DRE) suspicion ( P = 0.03) at diagnosis. Our reports confirm that Moroccan men with prostate cancer have higher PSA, PSA density and aggressive Gleason grade at diagnosis and that symptoms presentation increase along with age and are significantly related to the abnormality of DRE.

Association of tumor infiltrating lymphocytes with pathological response after neoadjuvant therapy in breast cancer: A retrospective study.

e12621 Background: Tumor infiltrating lymphocytes (TILs) are thought to represent favorable host anti-tumor immunity and play an important role in mediating response to chemotherapy in breast cancer. TILs are heterogenous across breast cancer subtypes and are increasingly being studied as prognostic and predictive biomarkers. We undertook a retrospective study to establish the relationship between pre-treatment density of TILs and subsequent quality of response to neoadjuvant chemotherapy in patients with early-stage breast cancer. Methods: We retrospectively identified women with breast cancer who had received neoadjuvant therapy (NAT) at the University of Cincinnati from 2012-2018. Clinical and pathological variables were extracted from medical records. Pre-treatment core biopsies were assessed for intra-tumoral TILs through independent pathology review and were graded as mild (grade 1), moderate (grade 2) or severe (grade 3). Post-treatment resection samples were assessed for pathological complete response (pathCR). Univariate analysis was done to determine the association between TILs and pathCR. Results: We identified 148 patients with breast cancer who received NAT, median age 53 years (25-90), 77 were Caucasian. 32 patients had stage I disease at diagnosis, 87 stage II and 29 stage III. Most patients had tumor grade 2 (n=50) or 3 (n=91). 50 patients were HER2+, 65 ER/PR+ HER2- (HR+) and 33 had triple negative breast cancer (TNBC). 69 patients received anthracycline based NAT, 29 non-anthracycline based NAT and all HER2+ patients received anti-HER2 therapy. 72 patients had TILs grade 1, 54 grade 2 and 22 had grade 3. 50 patients achieved pathCR. On univariate analysis grade 2 and 3 TILs were associated with higher likelihood of pathCR compared to grade 1 (42.1% vs 25%, OR 2.18, [1.08 – 4.4], p = 0.029). There was no difference in pathCR between grade 2 and grade 3 TILs (40.7% vs 45.5%, OR 1.21 [0.45-3.29], p=0.12). Tumor grade 3 was associated with higher pathCR than grade 1 or 2 (41.8 vs 21.1%, OR 2.69 [1.26-5.75], p=0.01). Amongst breast cancer subtypes, pathCR was lower in HR+(13.8%) compared to TNBC (45.5%) or HER2+ (52%) with OR 0.15 (0.06-0.36), p&lt;0.01. Age, race, stage and type of chemotherapy were not associated with pathCR. On multivariate analysis, none of the variables retained significance. Conclusions: Our analysis shows that increased TILs density (grade 2 or 3) and higher tumor grade are associated with pathCR whereas HR+ breast cancer have a lower rate of pathCR after NAT. Immune characterization of TILs might be helpful in further refining the prognostic impact of TILs.[Table: see text]

Dual Graded Lattice Structures: Generation Framework and Mechanical Properties Characterization.

Additive manufacturing (AM) enables the production of complex structured parts with tailored properties. Instead of manufacturing parts as fully solid, they can be infilled with lattice structures to optimize mechanical, thermal, and other functional properties. A lattice structure is formed by the repetition of a particular unit cell based on a defined pattern. The unit cell’s geometry, relative density, and size dictate the lattice structure’s properties. Where certain domains of the part require denser infill compared to other domains, the functionally graded lattice structure allows for further part optimization. This manuscript consists of two main sections. In the first section, we discussed the dual graded lattice structure (DGLS) generation framework. This framework can grade both the size and the relative density or porosity of standard and custom unit cells simultaneously as a function of the structure spatial coordinates. Popular benchmark parts from different fields were used to test the framework’s efficiency against different unit cell types and grading equations. In the second part, we investigated the effect of lattice structure dual grading on mechanical properties. It was found that combining both relative density and size grading fine-tunes the compressive strength, modulus of elasticity, absorbed energy, and fracture behavior of the lattice structure.

Developing SonReb models to predict the compressive strength of concrete using different percentage of recycled brick aggregate

This study was conducted to determine the relationship between nondestructive and destructive tests in concrete cubes using different ratios of normal stone and recycled brick as coarse aggregates. Variations in the grade of concrete, density, and age were considered to make the model prediction more efficient in places where the use of recycled brick aggregates is common. Normal concrete grades M20, M25, and M30 were considered having density variation by replacing stone with recycled brick aggregate, and age by testing concrete strength at 7, 28, and 84 days. A regression model was created using artificial neural networks and multiple regression analyses. The study showed that the regression model developed using an artificial neural network predicted better results. The models obtained from the experiment were compared with other models provided by different authors. The study also considered the effect of using recycled brick aggregate in nondestructive tests and the modulus of concrete.

A Deep Learning Approach to Re-create Raw Full-Field Digital Mammograms for Breast Density and Texture Analysis.

To develop a computational approach to re-create rarely stored for-processing (raw) digital mammograms from routinely stored for-presentation (processed) mammograms. In this retrospective study, pairs of raw and processed mammograms collected in 884 women (mean age, 57 years ± 10 [standard deviation]; 3713 mammograms) from October 5, 2017, to August 1, 2018, were examined. Mammograms were split 3088 for training and 625 for testing. A deep learning approach based on a U-Net convolutional network and kernel regression was developed to estimate the raw images. The estimated raw images were compared with the originals by four image error and similarity metrics, breast density calculations, and 29 widely used texture features. In the testing dataset, the estimated raw images had small normalized mean absolute error (0.022 ± 0.015), scaled mean absolute error (0.134 ± 0.078) and mean absolute percentage error (0.115 ± 0.059), and a high structural similarity index (0.986 ± 0.007) for the breast portion compared with the original raw images. The estimated and original raw images had a strong correlation in breast density percentage (Pearson r = 0.946) and a strong agreement in breast density grade (Cohen κ = 0.875). The estimated images had satisfactory correlations with the originals in 23 texture features (Pearson r ≥ 0.503 or Spearman ρ ≥ 0.705) and were well complemented by processed images for the other six features. This deep learning approach performed well in re-creating raw mammograms with strong agreement in four image evaluation metrics, breast density, and the majority of 29 widely used texture features.Keywords: Mammography, Breast, Supervised Learning, Convolutional Neural Network (CNN), Deep learning algorithms, Machine Learning AlgorithmsSee also the commentary by Chan in this issue.Supplemental material is available for this article.©RSNA, 2021.

Strength of cellular concrete as a function of density under axial uniaxial compression

The purpose of this work is a comparative analytical assessment of the axial compressive strength of foam concrete depending on its density grade, taking into account strength losses in the presence of surface-active substances, porosity, and strength characteristics of the matrix material. The values specified in GOST 25485-89 and calculated according to the proposed analytical laws and regulatory data are compared. The effect of the foaming reagent on the strength of the foam matrix was evaluated in accordance with GOST 30744-2001 on standard samples-beams 40x40x160 mm in size from the control cement test without additives and with additives of synthetic and protein foaming agents of different concentrations in the sealer (from 0.3 to 3%). The degree of influence of the foaming agent on the strength of the finished foam concrete prepared using classical technology was performed on samples-cubes of 100x100x100 mm in size according to GOST 10180-90. The article presents the results of a study of uniaxial compression strength calculated for cellular concrete depending on the density grades known from these regulatory documents and other sources. Analytical expressions for determining the strength calculated for cellular concrete with an average density of 300-900 kg/m3 are presented. The proposed approach, based on the assessment of the initial data – the strength class of the binder, porosity, matrix strength, type and concentration of the foaming agent-allows us to predict the final strength of foam concrete products of this average density. Their rational accounting will help in the production of construction products of the maximum possible strength at a given density. This will expand the use of foam concrete in construction.

Effect of Titanium on Itakpe Iron Ores Using Mathematical Modeling Approach with Respect to Second Law of Thermodynamic Principle

The objectives of this study were to evaluate the effect of titanium on iron ores and how it controls the strength, magnetization, and density (grade) of iron ores. The effectiveness of iron ores in Extractive Industry depends on the ratio of titanium to iron in the solid solution during crystallization of magma with respect to Gibbs free energy and can be mathematically expressed as, [Fe 3-x Ti x ]O 4 and [Fe 2-x Ti x ]O 3. Methodologically, 1Kg of each of five samples of iron ores were collected from Itakpe iron ore, which were pulverized and were compared with those that were obtained from 20Kg of Cassiterite after processing with the help of ordinary hand magnet of about 0.01Tesla. Findings have shown that, the high magnetization by ordinary hand magnet, with low strength and greater density of Itakpe iron ore indicated that the ores have not been affected by titanium. Conversely, the low magnetization by hand magnet with greater strength and lower density indicated that the ores from cassiterite have been affected by titanium. In conclusion, the presence or absence of titanium in an iron ore determines the types of magnetic separators used to separate the ores, as well as their genetic rock origin, in which the amount of titanium in iron ore increased from Basic, with ∆G = 0, e.g., basalt to more Acidic, with ∆G &gt; 0, e.g., granite which gives the account that oceanic basalt is more magnetic, more dense, weaker strength than the granite. After comparative analyses between Itakpe iron ores and cassiterite in Jos Plateau state, using magnetism, strength, and density to appraise the iron ores according to titanium to iron ratio, concise valuable substantive empirical novel models were developed and can be employed to study iron ore. These concise empirical novel models were, “Matrix equations,” Oxidation and the Titanization, as well as Periodic Table of an iron ore, and can be recommended to study the effect of titanium on iron ores and the application can improve mineral processing in extractive Industry

Evaluation of corneal topography, tear film function and conjunctival impression cytology after long-term scleral contact lens wear in keratoconus patients

ABSTRACT Purpose: To investigate the impact of long-term scleral contact lens (ScCL) wear on corneal curvature, corneal thickness, tear film function, and ocular surface in patients with keratoconus.Methods: Sixteen keratoconus patients wearing ScCLs for 6 months were enrolled in the study. Corneal topography, tear osmolarity test, Schirmer 1 test, tear film break-up time (TBUT) test, and impression cytology analysis were assessed at baseline and follow-up examinations.Results: There were no significant differences in visual acuity, keratometric and pachymetric values after 6 months of ScCL wear compared to baseline (p>0.05 for all). Tear osmolarity, Schirmer 1 test, and TBUT test results showed no significant change during follow-up (p>0.05 for all). Median goblet cell density and grade of squamous metaplasia did not differ significantly at 1-month. However, there was a gradual deterioration in goblet cell density and Nelson grade until the third-month visit compared to baseline (p for goblet cell, p=0.003; p for Nelson grade, p=0.003). These impaired cytological features observed at 3-month visit persisted at 6-month visit (p for goblet cell, p=0.008; p for Nelson grade, p<0.001).Conclusion: Six months of ScCL wear did not induce any changes in corneal curvature and thickness and also did not affect tear function tests in keratoconic eyes. The only significant changes observed were a decrease in goblet cell density and metaplastic changes in conjunctival epithelium in impression cytology analysis. Further investigations may be needed to better understand the cause of impairment in cytological features of ocular surface and its clinical implications.

Uniaxial compression of bi-directionally graded lattice structures: Finite element modelling

Lattice structures are widely used in various engineering applications due to their high weight-to-strength ratio and exceptional energy absorbing performance. The feasibility of using different base materials to fabricate these cellular structures with complex geometries has been significantly broadened with the development of additive manufacturing technology. In this paper, quasi-static mechanical properties and energy absorption capability of polyamide PA 2200 (nylon 12) lattice structures were investigated by using finite element analysis (FEA) in ANSYS/LS-DYNA. Three types of lattice structures composed of body-centred cubic (BCC) unit cells were studied, including uniform lattice structures, uni-directionally graded lattice structures and bi-directionally graded structures. Finite element simulations were consistent with experimental data reported in literature. The results showed that bi-directionally graded lattice structures exhibited superior crushing resistance and higher energy absorption capacity than uniform and uni-directionally graded lattice structures. It showed that density grading design of lattice structures had significant influence on the deformation patterns and therefore, energy absorption performance.

The Effects of Antiglaucoma Ophthalmic Solutions on the Cornea Revealed by a Corneal Electrical Resistance Device.

Purpose: We sought to evaluate the effect of antiglaucoma ophthalmic solutions on the cornea with a corneal resistance device (CRD), and to compare the results with those by fluorescein staining. Methods: In 6 rabbit groups (n = 7 each), right eyes were administered latanoprost ophthalmic solution containing 0.02% benzalkonium chloride (BAK); dorzolamide/timolol (1%/0.5%) containing 0.005% BAK; dorzolamide/timolol without BAK; dorzolamide/timolol+latanoprost with 0.02% BAK; 0.005% BAK; or 0.02% BAK to the conjunctival sac 3 × at 15-min intervals. Left (control) eyes were administered saline. Baseline and post-treatment corneal resistance (CR) were measured. The CR ratio = CR before versus after treatment. We evaluated superficial punctate keratitis by fluorescein staining using area and density (AD) grades. Results: In the dorzolamide/timolol-without BAK group, there were no significant difference in the CR ratio between the control and treatment eyes at any time point. In the 0.005%-BAK group at 30 min and the other 4 groups at all time points, the CR ratio differed significantly between the control and treatment eyes (P < 0.05). AD grades were 0 in all control eyes and the dorzolamide/timolol-without BAK and 0.005% BAK treatment eyes. Conclusions: Nonpreservative ophthalmic solutions (and those with low BAK concentrations) do not significantly affect corneal electrical resistance. Eye drop ingredients other than BAK may be involved in altering corneal electrical resistance. CRDs may detect corneal epithelium changes not revealed by fluorescein staining.

Comparative Pull-Out Performances of Cephalomedullary Nail with Screw and Helical Blade According to Femur Bone Densities

This paper mainly examines the fixation performances of the cephalomedullary nail for the incidence of intertrochanteric (IT) fracture to guide the appropriate fixations with respect to the bone density in terms of a biomechanical perspective. It is substantially important to guide which types of fixation are applied during the operation since it tends to induce the backout or migration of the helical blade and screw according to weight and bone density. Biomedical polyurethane (PUR) foam blocks for simulating human bone are adopted with two grades of densities to simulate a normal person and an elderly person who has osteoporosis. Tensile and compression tests are conducted to analyze the tensile-compression anisotropy of PUR foams. Pull-out performances of screw and helical blades are evaluated from experimental perspectives, which are supported by comparison with the results of finite element method analysis. The clamping force of the screw is higher than the helical blade, about 177% in normal foam density and 198% in low foam density. After physical evaluation of the critical pull-out fixation force of screw and helical blade, we have suggested that stable fixation is guaranteed when the pull-out force is larger than projected force.

Pore Structure, Morphology, and Strength of Self-Compacting Foam Material Backfilled Behind the Underground Pipe-Wall of Yellow River.

The backfill material for the underground pipe wall of Yellow River embankment was developed to avoid the high settlement and environmental damage caused by high filling and excavation. The interrelation between microstructure and compressive strength of the self-compacting foam backfill material with different water–binder ratios and density grades was investigated. The results indicated that the average pores size of the foam backfill material increased with increasing the water–binder ratio. Moreover, the compressive strength of the foam backfill material first increased and then decreased with continuously increasing the water–binder ratio. Based on the observation and the analysis of the computed tomography (CT) image, it can be found that the pore size of the foam backfill material decreased with the increment of the density grade. The overall findings demonstrated that the pore size and volume played an important role in affecting the performance of the foam backfill material used for the construction of the underground pipe wall of Yellow River embankment.

Non-autoclaved foam concrete for layers of highways surface dressing

The article is devoted to the problems associated freeze with the calculated estimation of the parameters of the structural and heat-insulating antifreeze layer in the subgrade of non-rigid roads on various soil bases. The main physical, technical and deformation characteristics of monolithic dispersed non-autoclaved foam concrete reinforced with polypropylene fiber of grades of density from 600 to 1000 kg/m3 are investigated. Freezing of subsoil waters directly under the roadway pavement and, as a result, its increase in volume, leads to significant deformations of the road surface. Under such conditions, the period of defectfree operation of the roadway pavement is significantly reduced, which in turn leads to the need to repair it in a more intensive mode. One of the ways to reduce the operating cost and maintenance costs of the road transport infrastructure is to introduce into the design and construction practice new structural concepts for road surface dressing that ensure high quality pavement during the normative operational period. This can be achieved by introducing an effective heat-insulating material into the pavement structure as an anti-frost layer in order to elimi-nate the effect of frost lift of the roadway pavement of non-rigid roads. Since domestic and foreign experience freeze in the road construction has proven the effectiveness of the use of heatinsulating materials in the road surface dressing construction, in recent years in Ukraine there has been increased interest in the use of non-autoclaved foam concrete as a modern and highly effective heat-insulating material in road construction. The installation of a heat-insulating layer made of non-autoclaved foam concrete allows us to completely or partially prevent freezing or overheating of the surface dressing base, reduce the influence of periodic variations in environmental temperature, which in turn will increase the durability of the pavement structure. The publication presents nomograms for determining the optimal thickness of the heat-insulating anti-frost heavy course (layer) of road surface dressing (based on sand, loamy sand, clay and loam) done at the street and road network for all climatic and geographical regions of Ukraine.