Conventional Loading Method Research Articles

Isolated cardiac muscle contracting against a real-time model of systemic and pulmonary cardiovascular loads.

Isolated cardiac tissues allow a direct assessment of cardiac muscle function and enable precise control of experimental loading conditions. However, current experimental methods do not expose isolated tissues to the same contraction pattern and cardiovascular loads naturally experienced by the heart. In this study, we implement a computational model of systemic-pulmonary impedance that is solved in real time and imposed on contracting isolated rat muscle tissues. This systemic-pulmonary model represents the cardiovascular system as a lumped-parameter, closed-loop circuit. The tissues performed force-length work-loop contractions where the model output informed both the shortening and restretch phases of each work-loop. We compared the muscle mechanics and energetics associated with work-loops driven by the systemic-pulmonary model with that of a model-based loading method that only accounts for shortening. We obtained results that show simultaneous changes of afterload and preload or end-diastolic length of the muscle, as compared with the static, user-defined preload as in the conventional loading method. This feature allows assessment of muscle work output, heat output, and efficiency of contraction as functions of end-diastolic length. The results reveal the behavior of cardiac muscle as a pump source to achieve load-dependent work and efficiency outputs over a wider range of loads. This study offers potential applications of the model to investigate cardiac muscle response to hemodynamic coupling between systemic and pulmonary circulations in an in vitro setting.NEW & NOTEWORTHY We present the use of a "closed-loop" model of systemic and pulmonary circulations to apply, for the first time, real-time model-calculated preload and afterload to isolated cardiac muscle preparations. This method extends current experimental protocols where only afterload has been considered. The extension to include preload provides the opportunity to investigate ventricular muscle response to hemodynamic coupling and as a pump source across a wider range of cardiovascular loads.

Immediate Versus Conventional Loading of Two-Implant Overdenture with Magnetic Attachments: A 5-Year Follow-Up on Patient-Reported Outcomes

Comprehensive, long-term studies on patient-reported outcomes for two-implant overdentures with magnetic attachments using immediate or conventional loading methods are lacking. This study aimed to provide 5-year follow-up data comparing patient-reported outcomes for mandibular overdentures supported by two implants with magnetic attachments under immediate or conventional loading. Nineteen edentulous mandible patients were randomly assigned to immediate (IG) or conventional loading groups (CG). Two implants were placed with prostheses, loaded on the same day (immediate) or three months later (conventional). Participants completed questionnaires (oral health-related quality of life (OHRQoL), patient general satisfaction, and patient’s denture assessment (PDA)) at baseline and yearly intervals for 5 years. Results showed no significant differences between IG and CG throughout the study. However, the within-group analysis revealed significant improvements in OHRQoL, patient satisfaction, and all PDA domains from the baseline to years 1–5. Regarding patient satisfaction, significant differences were observed between T1, T2, and T3 when compared with T0 of IG and T1-T0 of CG. Regarding PDA results of T4-T5, IG exhibited several significant differences compared to CG. In conclusion, this study suggests that two-implant overdentures with magnetic attachments, whether immediately or conventionally loaded, improve patient-reported outcomes. Immediate loading may have prolonged effects on the improvement of patient-reported outcomes.

Research on the Symbolic 3D Route Scene Expression Method Based on the Importance of Objects

In the study of 3D route scene construction, the expression of key targets needs to be highlighted. This is because compared with the 3D model, the abstract 3D symbols can reflect the number and spatial distribution characteristics of entities more intuitively. Therefore, this research proposes a symbolic 3D route scene representation method based on the importance of the object. The method takes the object importance evaluation model as the theoretical basis, calculates the spatial importance of the same type of objects according to the spatial characteristics of the geographical objects in the 3D route scene, and constructs the object importance evaluation model by combining semantic factors. The 3D symbols are then designed in a hierarchical manner on the basis of the results of the object importance evaluation and the CityGML standard. Finally, the LOD0-LOD4 symbolic 3D railway scene was constructed on the basis of a railroad data to realise the multi-scale expression of symbolic 3D route scene. Compared with the conventional loading method, the real-time frame rate of the scene was improved by 20 fps and was more stable. The scene loading speed was also improved by 5–10 s. The results show that the method can effectively improve the efficiency of the 3D route scene construction and the prominent expression effect of the key objects in the 3D route scene.

Immediate loading of short implants: A systematic review.

Background This systematic review aimed to determine the effectiveness and outcomes of immediate loading methods for short dental implants. Methods The authors independently conducted an electronic search in the PubMed, Embase, EBSCO, ProQuest, and Cochrane databases for relevant articles published until November 15, 2020. The references of the included studies were assessed, and a manual search was conducted in Google Scholar and PubMed to find additional relevant studies. Results Finally, three studies were selected and included in this systematic review. Significant heterogeneity existed in the design of the included studies, and due to the low number of the included studies, the authors could not perform a meta-analysis. The studies showed that the survival rate of immediate-loaded short implants is comparable to conventional loading Methods. However, more marginal bone loss is expected. Overall, the immediate loading of short dental implants might be clinically successful.Conclusion Based on the results, immediate loading protocols might be safely used for short implants. However, caution should be exercised in interpreting these results.Future welldesigned randomized clinical trials with more participants and study power are necessary to support the findings of this systematic review.

Application of common-path speckle interferometer with unlimited minimal shearing amount to characterization of irregularly shaped notch

Non-destructive evaluation (NDE) techniques are widely used to detect and characterize different defects in engineering structures. However, the highly sensitive real-time quantitative imaging of irregularly shaped defects in large-area metallic structures remains challenging if conventional NDE approaches are used. In this paper, a speckle interferometer with unlimited minimal shearing amount – based on a simple imaging setup without the need to tilt any optical components – is explored for the application of detection and characterization of complex-shaped defects in metallic plates. This technology is able to directly yield strain measurements, allowing the defects to be detected by identifying induced strain concentrations under stress loading. Acoustic waves are used as stress loading for this imaging system with the advantage of a deeper penetration depth and a larger area of inspection as compared to conventional loading methods, e.g. thermal loading. The spatial carrier technique is introduced to quantitatively reconstruct the phase distribution, which contains information of the strain measurement from a single recording. To achieve the near real-time imaging of defects with relative insensitivity against noise, the image pairs are continuously recorded and correlated using the sequential subtraction method. The performance of the imaging system was tested with experimental data. The results demonstrate that the imaging system can generate high-quality images to provide good detection and characterization properties regarding irregularly shaped notches as well as accurate sizing of different notch dimensions. This work introduces a promising practical NDE tool for the near real-time, non-contacting and quantitative detection of subsurface defects with complex geometries in large-area metallic structures.

Activation of Water‐Splitting Photocatalysts by Loading with Ultrafine Rh–Cr Mixed‐Oxide Cocatalyst Nanoparticles

AbstractThe activity of many water‐splitting photocatalysts could be improved by the use of RhIII–CrIII mixed oxide (Rh2−xCrxO3) particles as cocatalysts. Although further improvement of water‐splitting activity could be achieved if the size of the Rh2−xCrxO3 particles was decreased further, it is difficult to load ultrafine (<2 nm) Rh2−xCrxO3 particles onto a photocatalyst by using conventional loading methods. In this study, a new loading method was successfully established and was used to load Rh2−xCrxO3 particles with a size of approximately 1.3 nm and a narrow size distribution onto a BaLa4Ti4O15 photocatalyst. The obtained photocatalyst exhibited an apparent quantum yield of 16 %, which is the highest achieved for BaLa4Ti4O15 to date. Thus, the developed loading technique of Rh2−xCrxO3 particles is extremely effective at improving the activity of the water‐splitting photocatalyst BaLa4Ti4O15. This method is expected to be extended to other advanced water‐splitting photocatalysts to achieve higher quantum yields.

Activation of Water-Splitting Photocatalysts by Loading with Ultrafine Rh-Cr Mixed-Oxide Cocatalyst Nanoparticles.

The activity of many water‐splitting photocatalysts could be improved by the use of RhIII–CrIII mixed oxide (Rh2−xCrxO3) particles as cocatalysts. Although further improvement of water‐splitting activity could be achieved if the size of the Rh2−xCrxO3 particles was decreased further, it is difficult to load ultrafine (<2 nm) Rh2−xCrxO3 particles onto a photocatalyst by using conventional loading methods. In this study, a new loading method was successfully established and was used to load Rh2−xCrxO3 particles with a size of approximately 1.3 nm and a narrow size distribution onto a BaLa4Ti4O15 photocatalyst. The obtained photocatalyst exhibited an apparent quantum yield of 16 %, which is the highest achieved for BaLa4Ti4O15 to date. Thus, the developed loading technique of Rh2−xCrxO3 particles is extremely effective at improving the activity of the water‐splitting photocatalyst BaLa4Ti4O15. This method is expected to be extended to other advanced water‐splitting photocatalysts to achieve higher quantum yields.

Composite filler by pre-flocculation of fiber fines and PCC and its effect on paper properties

Abstract A composite filler was developed by pre-flocculation of fiber fines and precipitated calcium carbonate (PCC) particles with flocculants such as cationic polyacrylamide (cPAM) and bentonite. The composite filler was compared with a conventional loading method in terms of physical properties of handsheet and filler retention. The handsheets using the composite filler showed higher strength properties than that using a conventional loading at a similar paper ash content level, implying that paper ash content can be increased maintaining same level of paper strength. Optical properties such as opacity and brightness of the paper with the composite were quite similar with the paper with the conventional loading. Filler retention of the composite filler was slightly higher than that of the conventional loading even though retention aids were not used for the composite filler. Paper formation of the composite filler was better than the case of the conventional loading. However, the sheet with the composite filler showed lower bulk than that with the conventional loading. Conclusively, the composite filler technology by pre-flocculation of fines and filler has a potential to be utilized to produce a high loaded paper.

Mesoporous black TiO2 array employing sputtered Au cocatalyst exhibiting efficient charge separation and high H2 evolution activity

The separation and transfer of photogenerated carriers are the key issue in the design of high performance TiO2 photocatalysts. In order to overcome the kinetic limitations and achieve rapid charge transfer, TiO2-related multi-component catalysts have been extensively studied. Among all the TiO2 supports, the impressive black TiO2 (BT) with broad visible light absorption spectrum and oxygen vacancies are preferable, but still suffers from low quantum efficiency. Meanwhile, poor control of cocatalyst placement by conventional loading method can also severely impede photocatalytic efficiency. Herein a fast and simple metal magnetron sputter approach was used to place highly-uniformed Au nanoparticles cocatalyst on the top of the mesoporous TiO2–BT nanotube array fabricated by in situ electrochemical anodization approach on a Ti film. This confined plasmonic photocatalyst with highly uniformly distributed Au cocatalysts exhibited greatly enhanced charge-separation and charge-transfer behavior, and a remarkable 10 times enhancement of the photocatalytic H2 evolution reactivity over conventional TiO2 nanotube. The TiO2-BT-Au electron transfer cascade structure is proposed in which black TiO2 acts as a buffer layer for TiO2 conduction band electrons, allowing efficient photogenerated electrons to be transferred to Au nanoparticles and then into the TiO2 pores that suitable for H2 generation. Since the nanotube walls themselves are curved upwards, the short diffusion length allows electrons to be easily transferred to the cocatalyst, where recombination of photogenerated electron pairs is limited. The metal magnetron sputter technique for noble metal cocatalyst immobilization and the unique TiO2–BT–Au electron-transfer system are promising and can be extended to the design of other supported catalysts.

A Universal Method for Acquiring the Constitutive Behaviors of API -5 L X90 Welds

The uniform elongation, which is the key factor to the constitutive behavior, is generally calculated by the Considere criterion, i.e., the uniform elongation equates the work-hardening exponent. However, it is found in this study that the widely used Considere criterion is not applicable to metals when the materials are subjected to the maximum load, as the first derivative of the fitted constitutive behavior is not zero which is the basic assumption in Considere criterion. To acquire the whole constitutive behaviors, an accurate and universal method is proposed, based on the work-hardening exponent and yield strength, to calculate the uniform elongation beforehand. With the yield strength obtained via the DIC data, and the work-hardening exponent determined by fitted Ramberg-Osgood model, the uniform elongation can be calculated by the new proposed method. The accuracy of the new method is validated by the conventional load method, indicating that the proposed method is applicable and feasible. With the uniform elongation calculated by the proposed method, the whole constitutive behavior of API 5 L X90 welds can be easily obtained.

The Improvement of Recycled Newsprint Properties by In-situ CaCO3 Loading

In-situ CaCO3 loading of old newspaper (ONP) fiber furnish was studied as a method to improve the properties of recycled newsprint paper. The effects of in-situ loading on the morphological and physical properties of ONP furnish were examined comparatively with conventional loading methods (addition of ground or precipitated CaCO3, without and with pre-flocculation treatment). The effective residual ink content (ERIC) and macro sticky content began to decrease as soon as the in-situ CaCO3 formation started by the injection of carbon dioxide to the reaction tank, where the ONP furnish and calcium oxide mixture was agitated in high shear. When the reaction finished at pH 7, there were no more decreases of ERIC value and sticky content. Improvement of first pass retention and brightness was significant for the in-situ CaCO3 loading method. The decrease in breaking length with the addition of CaCO3 in the in-situ formation method was equivalent to or slightly lower than that of the CaCO3 pre-flocculation method, which is a method well known to give higher strength properties. Optical images from the FlowCAM® dynamic imaging particle analyzer showed strongly attached organic (fines) and inorganic (CaCO3) materials in the in-situ CaCO3 loading method.

Influence of natamycin loading methods on the physical characteristics of alginate active films

Natamycin, an antimicrobial agent sparingly soluble in water, was incorporated into alginate films in order to produce antimicrobial packaging, using three different approaches: the conventional loading method, when natamycin is added directly to the polymeric aqueous film-forming solution; the immersion procedure, by which a previously prepared films is contacted with natamycin solution, and by the supercritical solvent impregnation (SSI) method, with loading tests performed in CO2 containing natamycin, with and without addition of cosolvent (ethanol, 10% molar). The loading capacities were evaluated, as well as the influence on physical attributes of the films and on the release behavior of natamycin in water. The conventional method led to films heterogeneities with high surface roughness, and the immersion technique evinced several disadvantages like low incorporation yields, and negative influence on water vapor permeability and on the swelling degree of the film. The supercritical method showed that longer contact times and the use of ethanol as a cosolvent increased the natamycin loading yields and led to homogeneous films, where SSI (CO2+EtOH) process produced visually attractive and tranlucent films.

Enhanced photocatalytic hydrogen evolution over Pt supported on mesoporous [formula omitted] prepared by single-step sol–gel process with surfactant template

Nanocrystalline mesoporous TiO 2 photocatalyst with narrow pore size distribution was synthesized by a surfactant-assisted templating sol–gel technique and used as a support for Pt towards photocatalytic H 2 evolution. Single-step sol–gel (SSSG) method, in which Pt precursor was introduced into the completely hydrolyzed TiO 2 sol prepared with a mesopore-directing surfactant template, was utilized to load the Pt cocatalyst onto the synthesized mesoporous TiO 2 . In comparison, the conventional loading methods namely incipient wetness impregnation (IWI) and photochemical deposition (PCD) were also performed. The mesoporous Pt / TiO 2 photocatalyst prepared by the SSSG method showed higher photocatalytic activity for H 2 evolution over entire range of Pt loading content (optimum loading of 0.6 wt%) as well as broader photocatalytic activity window with respect to the amount of loaded Pt than those prepared by the other two methods and Pt/Degussa P-25 TiO 2 . Hence, the SSSG method has been postulated as a beneficial alternative for synthesis of effective metal-loaded mesoporous photocatalyst.

Hardness characterisation of thin Zr(Hf,N) coatings

In this study, depth-sensing Vickers indentation tests were conducted on Zr(Hf,N) coatings, containing different amounts of Hf (0–21 wt.%). The coatings were deposited on hardened AISI D2 cold-work tool steel with a physical vapour deposition technique. Hardness characteristics of the coatings were analysed under six different indentation loads (0.01–0.1 N) according to load and energy methods. The same Vickers hardness numbers were obtained from the conventional load method under indentation loads that create indents having depths lower than 10% of the coating thickness. An energy method, which was derived from the work of indentation, gave similar Vickers hardness numbers over a wide range of indentation depths (up to 25% of the coating thickness). The hardness numbers of Zr(Hf,N) coatings calculated by these two methods, which are independent of the indentation depth, did not change with increasing Hf content of the coatings. The average Vickers hardness number obtained from the energy method is approximately half that from the load method. After correcting the conventional-load-method HV numbers according to the Oliver and Pharr procedure, the difference between HV numbers calculated by load and energy methods significantly decreased.