Incorporation of Hydroxyapatite (HA) and Calcium Triphosphate (TCP) in the Epoxy Resin-Based Sealer

Objective This study aims to assess and compare the influence of hydroxyapatite (HA) and tricalcium phosphate (TCP) nanoparticles on a commercially available epoxy resinbased sealer, focusing on porosity and push-out bond strength. Materials and Methods This work was classified into a control group and two experimental groups. In each experimental group, the sealer was mixed with 2.5 wt.% of HA and TCP nanoparticles. Thirty extracted single-rooted teeth were utilized. After sectioning the crowns, the remaining roots of 15 teeth were used, up to 40 to 0.06, using a K3 rotary system. Smear layers were removed with 3 mL of 17% EDTA applied for 60 seconds. Then, the canals were irrigated with 3 mL of 2.25% NaOCl and 5 mL of distilled water. The strength of push-out bonds was tested via an Instron universal testing machine on a 2 mm section acquired from obturated canals. Data were assessed using one-way ANOVA and post hoc tests at a significance level of p < 0.05. Results A nonsignificant difference (p > 0.05) was evident when the three groups were crosschecked in terms of void volume and bond strength. Micro-CT evaluations revealed the lowest volume of voids to be 0.1152 mm3 (2.69%) for the HA group compared with the control group 0.1818 mm3 (3.9%) and the TCP group 0.2194 mm3 (4.33%). Mean bond strength values were 4.18 ± 1.77 MPa for group 1 (control), 4.19 ± 1.54 MPa for group 2 (HA 2.5%) and 3.76 ± 1.95 MPa for group 3 (TCP 2.5%). Groups 1 and 3 showed both cohesive and a mixed type of failure, while group 2 showed adhesive and a mixed type of bond failure. Conclusion Within the limitations of the study, incorporation of 2.5 wt% HA and TCP nanoparticles into AH Plus did not significantly affect the percentage volume of voids and the bond strength negatively.

Relationship between Density and Early Compressive Strength of Slurry Infiltrated Fiber Reinforced Concrete (SIFCON)

The aim of the study is to study the physical and mechanical characteristics of Slurry Infiltrated Fiber Reinforced Concrete with fiber percentage volume of 5% and lower. For the testing of physical characteristics of the concrete, density test been conducted. For the testing of mechanical characteristics, compression test used to determine strength of concrete sample. The density of Slurry Infiltrated Fiber Reinforced Concrete increased when the usage of steel fiber percentage volume increases from 1% to 5%, nevertheless when compared to density of ordinary concrete, ordinary concrete is denser. For the significant of study, the mechanical properties of Slurry Infiltrated Fiber Reinforced Concrete, compressive strength increased when the fiber content increases from 1% to 5% percentage volume.

The role of Street condition and forms on the amount of carbon emissions released from vehicles

In the last two decades, the percentage volume of carbon emissions has increased from 280 to more than 380 parts per million in the atmosphere, the problem is that it is still increasing daily in which it caused many environmental hazard that has been seen the last couple of years. The end of this century, It is expected that the uncontrolled amount of emissions emitted to the atmosphere will increase the surface temperature of plant earth by 3.4ºC. Worldwide, the percentage of carbon emissions in the atmosphere and its effect on air quality has been the main concern of scientist and researchers in the past decade. Egypt, is one of the biggest emitters that surfer from atmospheric pollution, almost 24% of the atmosphere pollutants in Egypt is from the transportation sector due to the heavy use of fossil fuels. Reducing the roads carbon emissions through streets design and form is the main scope of this research. This research intend to control the amount of carbon emission released in air by vehicles through controlling vehicles speed and motion which is effected by the street design and form. The presented research analysis the relation between carbon emissions and streets condition and forms, through measuring the amount of CO2 and CO emission produced in one of the Egyptian roads from different types of vehicles in road with three different conditions. El-Shuhada Street has been chosen to be the study area of this research. The researchers used Testo 315-3 to measure the Carbon emissions in the street and to identify the relation between CO2 emission and street condition and form. The results reveled that straight routes with vehicale speeds ranged between 80 to 100 kn/h produces less carbon emissions then straight routes with street bumps and vehicle speed ranged between 26 to 19 km/h. Moreover, curved routes emitted more emission than straight routes

Kaji Eksperimen Terhadap Penggunaan Bahan Bakar Emulsi Pada Burner

The purpose of this study was to observe the combustion of diesel fuel combined with the percentage volume of water and emulsifier, namely alkyl benzene sulfonic acid (ABS). The emulsion fuel composition used in this experimental study is a mixture of diesel fuel, emulsion and water. The composition of the emulsion fuel is designed according to the percentage of water volume and the emulsifier in diesel fuel with a variation of the percentage of 10%, 20%, and 30%. The parameters observed were combustion flame temperature, combustor annulus wall temperature, hot gas temperature, air fuel ratio (AFR), heat loss, and flame shape from differences in the composition of the percentage volume of emulsion fuel. In this test using Combustion Laboratory Unit C 491. The results showed that the heat absorbed due to cooling (Qa) in the AFR stoichiometry of diesel fuel (diesel) 26.334 kW was smaller than emulsion fuel (30.096 kW), so the use of emulsion fuel on the Burner Combustion Laboratory Unit C 49 is very suitable. The shape of the flame produced by the combustion of emulsion fuel is short, turbulent, and covered in water vapor.

Comparison of Obturation Quality after MTA Orthograde Filling with Various Obturation Techniques

This study aimed to quantify and compare the obturation quality after mineral trioxide aggregate (MTA) orthograde fillings with three different obturation techniques. Thirty-three extracted human maxillary molars were collected. Distobuccal and palatal canals were prepared to an apical size of #40/06 with a Profile Ni-Ti system. All 66 canals were divided into two groups according to the material (EZ-seal or OrthoMTA) and then obturated using three different techniques: manual compaction using S-kondenser (group H), compactor activation (group C), or reverse rotary motion of Ni-Ti file (group R). The obturated roots were scanned using micro-computed tomography (micro-CT). The percentage of voids located in the apical 5 mm was measured separately, that is, closed, open, and total porosity. There was no relation between the filling material and obturation technique (p > 0.05). The percentage volume of open and total porosity was higher in EZ-seal than in OrthoMTA (open: p = 0.002, total: p = 0.001). Group H showed higher open and total porosity than groups C and R. Micro-CT analysis showed that the void volume after orthograde MTA fillings significantly decreased when the additional activation was accompanied by hand condensation. Obturation with a Ni-Ti file using reverse motion could be recommended as an MTA orthograde filling technique.

Comparison of Ray Tracing and Monte Carlo Calculation Algorithms for Spine Lesions Treated with CyberKnife

Purpose: This study attempts to evaluate Ray Tracing (RT) and Monte Carlo (MC) algorithm for CyberKnife treatments of spine lesions and determine whether MC algorithm is necessary for all spine treatment and analyze which sites of spine lesion for which RT algorithm is comparable to MC algorithm. Methods: The CyberKnife is used for stereotactic body radiotherapy for lesions in the cervical spine (30), thoracic spine (50), lumbar spine (30) and sacral spine (15). Dose was calculated using RT and MC algorithms for patients planned with the same beam angles and monitor units. Dose-volume histograms of the target and selected critical structures are evaluated. Results: The average target coverage of prescribed dose with MC algorithms was 94.80%, 88.47%, 92.52% and 93.41% respectively in cervical, thoracic, lumbar and sacral spine. For thoracic spine, RT algorithm significantly overestimates the percentage volume of target covered by the prescribed dose, as well as overestimates doses to organs at risk in most cases, including lung, spinal cord and esophagus. For cervical, lumbar and sacral spine, the differences of the target coverage of prescription dose were generally less than 3% between the RT and MC algorithms. The differences of doses to organs at risk varied with lesion sites and surrounding organs. Conclusions: In the thoracic spine lesions with beams through air cavities, RT algorithm should be limited and verified with MC algorithm, but the RT algorithm is adequate for treatment of cervical, lumbar and sacral spine lesions without or small amount of beams passing through the lungs.

Micro-CT Evaluation of Four Root Canal Obturation Techniques

Purpose. The aim of this in vitro study was to evaluate the quality of four root canal obturation techniques using microcomputed tomography (micro-CT). Materials and Methods. A total of 36 mandibular first premolars with mostly round canals were decoronated, then instrumented up to a size F3 rotary file, and dressed with an epoxy resin-based sealer. Subsequently, they were divided into 4 different groups ( n = 9 ) based on the method of obturation: lateral condensation using 0.02 tapered master cone (LC2), lateral condensation using 0.04 tapered master cone (LC4), matched single-cone technique (MS), and matched single cone-mediated ultrasonic activation (MSUA). All the teeth were scanned using micro-CT (resolution of 19 μm), and the percentage volume of voids was calculated. One-way analysis of variance and Tukey test were used to analyze the data ( α = 0.05 ). Results. The total percentage volume of voids was significantly lower in the MSUA group compared to all other groups ( P < 0.05 ). The total percentage volume of voids was significantly lower in the MS group compared to the LC4 ( P < 0.001 ) and LC2 ( P < 0.001 ) groups. However, there was no significant difference between the LC2 and LC4 groups ( P < 0.65 ). Conclusions. MSUA, significantly, showed the least root canal filling voids amongst all the obturation techniques studied. MSUA can be considered an effective method for the filling of the round root canals. In general, lateral condensation using either 0.02 or 0.04 tapered master cones had significantly the highest volume percentage of voids amongst the experimental groups.

Prostate cancer measurements on serial MRI during active surveillance: it’s time to be PRECISE

Objective: The PRECISE criteria for reporting multiparametric MRI in patients on active surveillance (AS) for prostate cancer (PCa) score the likelihood of clinically significant change over time using a 1–5 scale, where 4 or 5 indicates radiological progression. According to the PRECISE recommendations, the index lesion size can be reported using different definitions of volume (planimetry or ellipsoid formula) or by measuring one or two diameters. We compared different measurements using planimetry as the reference standard and stratified changes according to the PRECISE scores. Methods: We retrospectively analysed 196 patients on AS with PCa confirmed by targeted biopsy who had two MR scans (baseline and follow-up). Lesions were measured on T2 weighted imaging (T2WI) according to all definitions. A PRECISE score was assessed for each patient. Results: The ellipsoid formula exhibited the highest correlation with planimetry at baseline (ρ = 0.97) and follow-up (ρ = 0.98) imaging, compared to the biaxial measurement and single maximum diameter. There was a significant difference (p < 0.001) in the yearly percentage volume change between radiological regression/stability (PRECISE 2–3) and progression (PRECISE 4–5) for planimetry (39.64%) and for the ellipsoid formula (46.78%). Conclusion: The ellipsoid formula could be used to monitor tumour growth during AS. Evidence of a significant yearly percentage volume change between radiological regression/stability (PRECISE 2-3) and progression (PRECISE 4-5) has been also observed. Advances in knowledge: The ellipsoid formula is a reasonable surrogate for planimetry in capturing tumour volume changes on T2WI in patients on imaging-led AS. This is also associated with radiological changes using the PRECISE recommendations.

Study the Effect of Catalyst -to- Oil Ratio Parameter (COR) on Catalytic Cracking of Heavy Vacuum Gas Oil

This work deals with the production of light fuel cuts of (gasoline, kerosene and gas oil) by catalytic cracking treatment of secondary product mater (heavy vacuum gas oil) which was produced from the vacuum distillation unit in any petroleum refinery. The objective of this research was to study the effect of the catalyst -to- oil ratio parameter on catalytic cracking process of heavy vacuum gas oil feed at constant temperature (450 °C). The first step of this treatment was, catalytic cracking of this material by constructed batch reactor occupied with auxiliary control devices, at selective range of the catalyst –to- oil ratio parameter ( 2, 2.5, 3 and 3.5) respectively. The conversion of heavy vacuum gas oil which was obtained, reaches to (50, 70, 75 and 80) % for (2, 2.5, 3 and 3.5 catalysts -to- oil ratio parameter respectively. The second step for this study was distillation of this cracking heavy vacuum gas oil liquid by atmospheric distillation device for these several catalyst -to- oil ratio parameter, according to obtained light fuel cuts (gasoline, kerosene and gas oil). The percentage volume of light fractions at various COR are (7, 25 and 18) for COR 2, (10, 20 and 40) for COR 2.5, (10, 30 and 35) for COR 3 and (15, 30 and 35) for COR 3.5 which separates according to its boiling point. The light cuts were distilled by atmospheric distillation device in order to obtained distillation curve. The third step was study the major physical and chemical properties for feed (heavy vacuum gas oil) and catalytic cracking liquid of HVGO at various COR with its light fuel fractions, the results refers to acceptable properties compared with other commercial properties.