Determination of impregnation parameters and volatile components in vacuum impregnated apricots.

An investigation was conducted to analyse the impact of vacuum impregnation (VI) on aroma profile of intermediate-moisture apricots. cv. Hacihaliloglu and cv. Kabaasi apricots were immersed in a variety of solutions, including citric acid and sucrose, as well as plant extracts like rosehip, roselle, and rhubarb. According to the results, solid loss and water gain were observed in all infused samples by VI, while osmotic dehydration occurred in the apricots after immersing in sucrose solution. After all process, a total of 71 volatile compounds were detected in the Hacihaliloglu variety and 66 in the Kabaasi variety. These components are aldehydes, ketones, esters, furan compounds, alcohols, terpenes, isoprenoids, and acids, collected in eight groups. Vacuum impregnation had positive effects on terpenes in both cultivars.

Optimizing metal part distortion in the material extrusion-thermal debinding-sintering process: An experimental and numerical study.

The thermal debinding-sintering process plays an essential role in the context of material extrusion-based additive manufacturing (AM) for producing parts using metal injection molding (MIM). During thermal debinding, metal parts often experience material distortion and porosity, which negatively impacts their mechanical properties. Slowing down the debinding speed is a common approach to mitigate material distortion and porosity. However, this leads to a significant increase in the debinding time. In this study, we carried out debinding-sintering experiments to optimize the distortion and porosity in metal parts. These metal parts were manufactured utilizing bronze/polylactide (PLA) blend filaments and placed in crucibles of different sizes (small, medium, and large), with different heating rates and holding times. The results revealed that the small crucible yielded higher porosity levels in the metal parts, which could be reduced from 23% to 12% by extending both the heating and holding times. In contrast, the medium crucible managed to reduce porosity to approximately 15% without requiring an extension of the processing time. The large crucible, on the other hand, couldn't achieve further porosity reduction due to challenges in reaching the desired temperature. To gain a deeper insight into temperature distribution during the debinding process, we performed numerical simulations using the computational fluid dynamics (CFD) technique and obtained temperature profiles within the kiln using the three crucibles. Ultimately, we carried out standard mechanical tests on the resulting metal parts and evaluated the thermal debinding procedure under various conditions. The approach we employed, combining experiments and numerical simulations, demonstrated significant promise for enhancing the quality of metal parts in the thermal debinding-sintering process.

Defective UiO-66/cellulose nanocomposite aerogel for the adsorption of heterocyclic aromatic amines.

Heterocyclic aromatic amines (HAAs), arising as chemical derivatives during the high-temperature culinary treatment of proteinaceous comestibles, exhibit notable carcinogenic potential. In this paper, a composite aerogel (AGD-UiO-66) with high-capacity and fast adsorption of HAAs was made with anchoring defective UiO-66 (D-UiO-66) mediated by lauric acid on the backbone of cellulose nanofibers (CNF). AGD-UiO-66 with hierarchical porosity reduced the mass transfer efficiency for the adsorption of HAAs and achieved high adsorption amount (0.84-1.05 µmol/g) and fast adsorption (15 min). The isothermal adsorption model demonstrated that AGD-UiO-66 belonged to a multilayer adsorption mechanism for HAAs. Furthermore, AGD-UiO-66 was successfully used to adsorb 12 HAAs in different food (roasted beef, roasted pork, roasted salmon and marinade) with high recoveries of 94.65%-104.43%. The intrinsic potential of AGD-UiO-66 demonstrated that it could be widely applicable to the adsorption of HAAs in foods.

Preserving Mesoporosity in Type III Porous Liquids through Dual-layer Surface Weaving.

The fundamental limitation for pore preservation in a Type III porous liquid (T3PL) is the need for a small aperture from the porous filler to realize size exclusion of a bulky solvent. We present a dual-layer surface weaving strategy that can disregard this limitation and achieve micro- and mesoporous metal-organic framework (MOF)-based T3PLs even with apertures much larger than the solvent molecules. By first weaving a tight network of poly(tert-butyl methacrylate) on the MOF surface, the poly(dimethylsiloxane) (PDMS) solvent can be effectively excluded from the pores while smaller guest molecules such as CO2, C2H4, and H2O can freely access the interior, as confirmed by low-pressure adsorption isotherms. Further application of a PDMS-containing polymer coating helps lower the viscosity of the PL due to increased particle dispersibility. This strategy has resulted in the successful construction of T3PLs with aperture sizes up to 3.1 nm.

Biodeterioration of Cement and Cement-Polymer Mortars: Analysis of the Influence of the Structure and Distribution of Pores on the Humidity of Mortars Exposed to the Biological Environment.

The biodegradation of building materials refers to the problem of loss of performance due to biological agents, mainly dry rot fungi, moulds (filamentous fungi), bacteria and insects. Biocorrosion not only leads to the damage and deterioration of building materials, but can also pose a direct threat to human health. Inorganic building materials are a difficult substrate for microorganisms because they need food sources for their metabolism. However, they become colonised by microorganisms. In this paper, the effect of mould fungi on the moisture content and structure of CEM I and CEM I cement-polymer mortars with a 5% polysiloxane latex admixture was analysed. The analysis was carried out after 15 months of exposure to the biological environment. It was found that the cementitious materials were susceptible to the corrosive environment in the form of the filamentous fungi Penicillium chrysogenum and Cladosporium herbarum. It was also found that, after 15 months of exposure to mould fungi, CEM I cementitious materials without admixtures were slightly less susceptible to mould fungi than CEM I with the addition of a 5% polysiloxane admixture.

A Novel Approach of Polyvinyl Alcohol/Acrylic Acid Based Hydrogels for Controlled Delivery of Diclofenac Sodium.

AIM AND OBJECTIVE: The aim of this study was to prepare polyvinyl alcohol/acrylic acid (PVA/AA) hydrogels for the controlled release of diclofenac sodium and to develop PVA/AA hydrogels as controlled release carriers to overcome not only the side effects of diclofenac sodium but also sustain its release for an extended period. BACKGROUND: Diclofenac sodium is employed for relieving pain and fever. The half-life of diclofenac sodium is very short (1-2 h). Hence, multiple intakes of diclofenac sodium are required to maintain a constant pharmacological action. Multiple GI adverse effects are produced as a result of diclofenac sodium intake. METHOD: A free radical polymerization technique was used for crosslinking PVA with AA in the presence of APS. EGDMA was used as a cross-linker. FTIR and XRD confirmed the preparation and loading of the drug by prepared hydrogels. An increase in the thermal stability of PVA was shown by TGA and DSC analysis. Surface morphology was investigated by SEM. Similarly, water penetration and drug loading were demonstrated by porosity and drug loading studies. The pH-sensitive nature of PVA/AA hydrogels was investigated at different pH values by swelling and drug release studies. RESULTS: The development and drug loading of PVA/AA hydrogels were confirmed by FTIR and XRD analysis. TGA and DSC indicated high thermal stability of prepared hydrogels as compared to unreacted PVA. SEM indicated a hard and compact network of developed hydrogels. The swelling and drug release studies indicated maximum swelling and drug release at high pH as compared to low pH values, indicating the pH-sensitive nature of prepared hydrogels. Moreover, we demonstrated that drug release was sustained for a prolonged time in a controlled pattern by prepared hydrogels by comparing the drug release of the developed hydrogels with the commercial product Cataflam. CONCLUSION: The results indicated that prepared PVA/AA hydrogels can be used as an alternative approach for the controlled delivery of diclofenac sodium.

Design of an Ultrasound Sensing System for Estimation of the Porosity of Agricultural Soils.

The design of a readily useable technology for routine paddock-scale soil porosity estimation is described. The method is non-contact (proximal) and typically from "on-the-go" sensors mounted on a small farm vehicle around 1 m above the soil surface. This ultrasonic sensing method is unique in providing estimates of porosity by a non-invasive, cost-effective, and relatively simple method. Challenges arise from the need to have a compact low-power rigid structure and to allow for pasture cover and surface roughness. The high-frequency regime for acoustic reflections from a porous material is a function of the porosity ϕ, the tortuosity α∞, and the angle of incidence θ. There is no dependence on frequency, so measurements must be conducted at two or more angles of incidence θ to obtain two or more equations in the unknown soil properties ϕ and α∞. Sensing and correcting for scattering of ultrasound from a rough soil surface requires measurements at three or more angles of incidence. A system requiring a single transmitter/receiver pair to be moved from one angle to another is not viable for rapid sampling. Therefore, the design includes at least three transmitter/reflector pairs placed at identical distances from the ground so that they would respond identically to power reflected from a perfectly reflecting surface. A single 25 kHz frequency is a compromise which allows for the frequency-dependent signal loss from a natural rough agricultural soil surface. Multiple-transmitter and multiple-microphone arrays are described which give a good signal-to-noise ratio while maintaining a compact system design. The resulting arrays have a diameter of 100 mm. Pulsed ultrasound is used so that the reflected sound can be separated from sound travelling directly through the air horizontally from transmitter to receiver. The average porosity estimated for soil samples in the laboratory and in the field is found to be within around 0.04 of the porosity measured independently. This level of variation is consistent with uncertainties in setting the angle of incidence, although assumptions made in modelling the interaction of ultrasound with the rough surface no doubt also contribute. Although the method is applicable to all soil types, the current design has only been tested on dry, vegetation-free soils for which the sampled area does not contain large animal footprints or rocks.

Combining raloxifene and mechanical loading improves bone composition and mechanical properties in a murine model of chronic kidney disease (CKD).

INTRODUCTION: Patients with chronic kidney disease (CKD) are at an alarming risk of fracture compared to age and sex-matched non-CKD individuals. Clinical and preclinical data highlight two key factors in CKD-induced skeletal fragility: cortical porosity and reduced matrix-level properties including bone hydration. Thus, strategies are needed to address these concerns to improve mechanical properties and ultimately lower fracture risk in CKD. We sought to evaluate the singular and combined effects of mechanical and pharmacological interventions on modulating porosity, bone hydration, and mechanical properties in CKD. METHODS: Sixteen-week-old male C57BL/6J mice underwent a 10-week CKD induction period via a 0.2 % adenine-laced casein-based diet (n = 48) or remained as non-CKD littermate controls (Con, n = 48). Following disease induction (26 weeks of age), n = 7 CKD and n = 7 Con were sacrificed (baseline cohort) to confirm a steady-state CKD state was achieved prior to the initiation of treatment. At 27 weeks of age, all remaining mice underwent right tibial loading to a maximum tensile strain of 2050 µÆ 3× a week for five weeks with the contralateral limb as a non-loaded control. Half of the mice (equal number CKD and Con) received subcutaneous injections of 0.5 mg/kg raloxifene (RAL) 5× a week, and the other half remained untreated (UN). Mice were sacrificed at 31 weeks of age. Serum biochemistries were performed, and bi-lateral tibiae were assessed for microarchitecture, whole bone and tissue level mechanical properties, and composition including bone hydration. RESULTS: Regardless of intervention, BUN and PTH were higher in CKD animals throughout the study. In CKD, the combined effects of loading and RAL were quantified as lower cortical porosity and improved mechanical, material, and compositional properties, including higher matrix-bound water. Loading was generally responsible for positive impacts in cortical geometry and structural mechanical properties, while RAL treatment improved some trabecular outcomes and material-level mechanical properties and was responsible for improvements in several compositional parameters. While control animals responded positively to loading, their bones were less impacted by the RAL treatment, showing no deformation, toughness, or bound water improvements which were all evident in CKD. Serum PTH levels were negatively correlated with matrix-bound water. DISCUSSION: An effective treatment program to improve fracture risk in CKD ideally focuses on the cortical bone and considers both cortical porosity and matrix properties. Loading-induced bone formation and mechanical improvements were observed across groups, and in the CKD cohort, this included lower cortical porosity. This study highlights that RAL treatment superimposed on active bone formation may be ideal for reducing skeletal complications in CKD by forming new bone with enhanced matrix properties.

Reservoir characterization of the Abu Roash D Member through petrography and seismic interpretations in Southern Abu Gharadig Basin, Northern Western Desert, Egypt.

This research combines petrography and seismic analysis to assess the Upper Cretaceous Abu Roash (AR)/D's carbonate member composition in the Southwest Abu-Sennan oil field in the Southern Abu Gharadig Basin within the Northern Western Desert of Egypt. Various datasets were used, including petrographic thin sections, and electrical well logs for four stratigraphic wells (01, -02, -03, and, -04), along with a time domain seismic dataset covering the study area. Petrographic analysis across multiple depths and intervals has provided valuable insights. Well-01 demonstrates mud-wackstone with diverse mineral components at 1671-74 m MD, indicating favorable reservoir quality. Well-02 exhibits diverse compositions at intervals 1740-43 m MD and 1746-49 m MD, also showcasing good reservoir quality. Well-03 reveals a packstone rock type at 1662-65 m MD with favorable reservoir characteristics. Well-04 displays peloids Wack-Packstone and Oolitic Packstone at intervals 1764-67 m MD and 1770-73 m MD, respectively, both indicating good reservoir quality. Integrating the petrography and seismic attributes results concerning the structural level of AR/D concerning the used wells, it's evident that Well-03 stands out due to its relatively high structural level, drilled near a major fault, revealing distinct fracture sets that contribute to a notably high reservoir quality as depicted in the RMS amplitude and Ant track attributes maps. AR/D reservoir levels in wells 02, and, 04, are relatively positioned at structurally lower levels, and face challenges with overburden pressure and mechanical compaction, resulting in diminished facies quality for the reservoir. Seismic attributes like the Ant track and RMS amplitude indicated that the presence of fractures within the AR/D Member's carbonate is linked to the prevalence of interpreted normal faults. The implemented procedure in this research can be applied to enhance comprehension of AR/D carbonate reservoirs in adjacent regions, thereby increasing the hydrocarbon exploration possibilities.

Mitigation of Gas Porosity in Additive Manufacturing Using Experimental Data Analysis and Mechanistic Modeling.

Shielding gas, metal vapors, and gases trapped inside powders during atomization can result in gas porosity, which is known to degrade the fatigue strength and tensile properties of components made by laser powder bed fusion additive manufacturing. Post-processing and trial-and-error adjustment of processing conditions to reduce porosity are time-consuming and expensive. Here, we combined mechanistic modeling and experimental data analysis and proposed an easy-to-use, verifiable, dimensionless gas porosity index to mitigate pore formation. The results from the mechanistic model were rigorously tested against independent experimental data. It was found that the index can accurately predict the occurrence of porosity for commonly used alloys, including stainless steel 316, Ti-6Al-4V, Inconel 718, and AlSi10Mg, with an accuracy of 92%. In addition, experimental data showed that the amount of pores increased at a higher value of the index. Among the four alloys, AlSi10Mg was found to be the most susceptible to gas porosity, for which the value of the gas porosity index can be 5 to 10 times higher than those for the other alloys. Based on the results, a gas porosity map was constructed that can be used in practice for selecting appropriate sets of process variables to mitigate gas porosity without the need for empirical testing.

Performance Analysis of Ferronickel Slag-Ordinary Portland Cement Pervious Concrete.

It is unknown whether Ferronickel slag (FNS)-ordinary Portland cement (OPC)-based pervious concrete (FOPC) is feasible. To this end, a feasibility study was conducted on FOPC. Firstly, a detailed microscopic examination of the FNS powder was conducted, encompassing analyses of its particle size distribution, SEM, EDS, and chemical composition. These analyses aimed to establish the suitability of a composite of FNS and OPC as a composite cementitious material. Subsequent experimentation focused on evaluating the compressive strength of the composite paste material with varying mixed proportions, revealing a slight reduction in strength as the FNS substitution rate increased. Furthermore, the study designed eighteen different mix proportions of FOPC to investigate the key physical properties, including porosity, density, compressive strength, and the coefficient of permeability. Findings indicated that increases in the cementitious material proportion correlate with enhanced concrete strength, where the ratio of cementitious to aggregate increased by 6.7% and 16.5%, and the strength of FOPC increased by 10-13% and 30-50%, respectively. Conversely, a rise in the FNS substitution rate led to a reduction in compressive strength across different mix ratios. Additionally, the ratio of paste material to aggregate was found to significantly influence the permeability coefficient. These comprehensive performance evaluations suggest that incorporating FNS into OPC for pervious concrete applications is a feasible approach, offering valuable insights for the promotion of waste reuse and the advancement of energy conservation and emissions reduction efforts.

Influences of Recycled Polyethylene Terephthalate Microplastic on the Hygrothermal and Mechanical Performance of Plasterboard with Polymethylhydrosiloxane Content.

New composites produced with recycled waste are needed to manufacture more sustainable construction materials. This paper aimed to analyze the hygrothermal and mechanical performance of plasterboard with a polymethylhydrosiloxane (PMHS) content, incorporating recycled PET microplastic waste and varying factors such as PMHS dose, homogenization time, and drying temperature after setting. A cube-centered experimental design matrix was performed. The crystal morphology, porosity, fluidity, water absorption, flexural strength, and thermal conductivity of plasterboards were measured. The results showed that incorporating recycled PET microplastics does not produce a significant difference in the absorption and flexural strength of plasterboards. However, the addition of recycled PET reduced the thermal conductivity of plasterboards by around 10%.

High Hydrogen Storage in Trigonal Prismatic Monomer-Based Highly Porous Aromatic Frameworks.

Hydrogen storage is crucial in the shift toward a carbon-neutral society, where hydrogen serves as a pivotal renewable energy source. Utilizing porous materials can provide an efficient hydrogen storage solution, reducing tank pressures to manageable levels and circumventing the energy-intensive and costly current technological infrastructure. Herein, two highly porous aromatic frameworks (PAFs), C-PAF and Si-PAF, prepared through a Yamamoto C─C coupling reaction between trigonal prismatic monomers, are reported. These PAFs exhibit large pore volumes and Brunauer-Emmett-Teller areas, 3.93 cm3 g-1 and 4857 m2 g-1 for C-PAF, and 3.80 cm3 g-1 and 6099 m2 g-1 for Si-PAF, respectively. Si-PAF exhibits a record-high gravimetric hydrogen delivery capacity of 17.01 wt% and a superior volumetric capacity of 46.5 g L-1 under pressure-temperature swing adsorption conditions (77 K, 100 bar → 160 K, 5 bar), outperforming benchmark hydrogen storage materials. By virtue of the robust C─C covalent bond, both PAFs show impressive structural stabilities in harsh environments and unprecedented long-term durability. Computational modeling methods are employed to simulate and investigate the structural and adsorption properties of the PAFs. These results demonstrate that C-PAF and Si-PAF are promising materials for efficient hydrogen storage.

Dual Brønsted acidic-basic function immobilized on the 3D mesoporous polycalix [4]resorcinarene: As a highly recyclable catalyst for the synthesis of spiro acenaphthylene/indene heterocycles.

In this study, a novel dual Brønsted acidic-basic nano-scale porous organic polymer catalyst, PC4RA@SiPr-Pip-BuSO3H, was synthesized through various steps: preparation of a 3D network of polycalix, modification with (3-chloropropyl)-trimethoxysilane, then functionalization of polymer with piperazine and n-butyl sulfonic acid under the provided conditions. The catalyst characterization was performed by FT-IR, TGA, EDS, elemental mapping, PXRD, TEM, and FE-SEM analyses, confirming high chemical stability, activity, recoverability, and excellent covalent anchoring of functional groups. So, the designed catalyst was utilized for preparing spiro-acenaphthylene and amino-spiroindene heterocycles, providing good performance with a high yield of the corresponding products. Accordingly, this catalyst can be used in different organic transformations. Necessary experiments were conducted for the recyclability test of the polymeric catalyst, and the results showed the PC4RA@SiPr-Pip-BuSO3H catalyst can be reused 10 times without any decrease in its activity or quality with excellent stability. The structure of resultant spiro heterocycles was confirmed using 1H NMR, 13C NMR, and FT-IR.

Exploring conventional and emerging dehydration technologies for slurry/liquid food matrices and their impact on porosity of powders: A comprehensive review.

The contribution of dehydration to the growing market of food powders from slurry/liquid matrices is inevitable. To overcome the challenges posed by conventional drying technologies, several innovative approaches have emerged. However, industrial implementation is limited due to insufficient information on the best-suited drying technologies for targeted products. Therefore, this review aimed to compare various conventional and emerging dehydration technologies (such as active freeze, supercritical, agitated thin-film, and vortex chamber drying) based on their fundamental principles, potential applications, and limitations. Additionally, this article reviewed the effects of drying technologies on porosity, which greatly influence the solubility, rehydration, and stability of powder. The comparison between different drying technologies enables informed decision-making in selecting the appropriate one. It was found that active freeze drying is effective in producing free-flowing powders, unlike conventional freeze drying. Vortex chamber drying could be considered a viable alternative to spray drying, requiring a compact chamber than the large tower needed for spray drying. Freeze-dried, spray freeze-dried, and foam mat-dried powders exhibit higher porosity than spray-dried ones, whereas supercritical drying produces nano-porous interconnected powders. Notably, several factors like glass transition temperature, drying technologies, particle aggregation, agglomeration, and sintering impact powder porosity. However, some binders, such as maltodextrin, sucrose, and lactose, could be applied in controlled agglomeration to enhance powder porosity. Further investigation on the effect of emerging technologies on powder properties and their commercial feasibility is required to discover their potential in liquid drying. Moreover, utilizing clean-label drying ingredients like dietary fibers, derived from agricultural waste, presents promising opportunities.

Hydroxyapatite-loaded macroporous calcium alginate hydrogels: Preparation, characterization, and in vitro evaluation.

Hydrogels from natural polysaccharides are of great interest for tissue engineering. This study aims (1) to prepare hydroxyapatite-loaded macroporous calcium alginate hydrogels by novel one-step technique using internal gelation in water-frozen solutions; (2) to evaluate their physicochemical properties; (3) to estimate their ability to support cell growth and proliferation in vitro. The structure of the hydrogel samples in a swollen state was studied by confocal laser scanning microscopy and was shown to represent a system of interconnected macropores with sizes of tens micron. The swelling behavior of the hydrogels, their mechanical properties (Young's moduli) in function of a hydroxyapatite content (5-30 mass%) were studied. All hydrogel samples loaded with hydroxyapatite were found to support growth and proliferation of mouse fibroblasts (L929) at long-term cultivation for 7 days. The obtained macroporous composite Ca-Alg-HA hydrogels could be promising for tissue engineering.

Size effect characteristics and influences on fatigue behavior of laser powder bed fusion of thin wall GRCop-42 copper alloy.

Size effects, influencing a material's strength, elongation, fatigue limit, and longevity, depend on the operative and dominant deformation and failure mechanisms. This study explores the size effects in additive manufactured (AM) GRCop-42 (Cu-4at%Cr-2at%Nb) thin wall structures fabricated via laser-powder bed fusion (L-PBF) and their impact on fatigue life. The influence of internal defects and surface topography on the fatigue life of specimens in both as-built and hot isostatic pressed (HIP) conditions across different thicknesses is investigated. Where micro-computed tomography (µCT) was used to quantify the internal porosity of as-built, pristine HIP'd, and fatigued HIP'd specimens, and laser microscopy was employed to quantify the surface topography of specimens prior to fatigue. Additionally, quasi-static tests were used to establish baseline mechanical properties (i.e. yield strength (YS), ultimate tensile strength (UTS), and elongation) to frame fatigue testing conditions. Results indicate a significant enhancement in fatigue life for HIP'd specimens for both thicknesses, with internal defects depicting a greater impact than surface topography. Furthermore, fractographic analysis suggests that thicker specimens exhibit higher resistance to crack propagation during fatigue testing in the absence of substantial porosity. Thus, the size effects observed on the fatigue life of L-PBF GRCop-42 appears to be dominated by internal defects.

Numerical investigation of the optimal porosity of titanium foam for dental implants.

Background: This paper aims to indicate numerically the accurate porosity used for dental implants, following the emphasis on the preference for titanium foam on pure titanium implants. A 3D-optimized numerical model is created to demonstrate the detailed differences between models. Method: A 3D finite element model was generated using Abaqus for titanium and titanium foam implants with different porosities (50,60,62.5,70, and 80%) fixed in cortical and cancellous bone. The mechanical data for titanium foam is extracted from published literature. We evaluate an artificial intelligent equation for the stress-strain response of titanium foam with various porosities to describe their variations. Results: To evaluate the stress-strain variations for different porosities, exponential artificial intelligence provides high accuracy (>0.99). The numerical results show that titanium foam implants appear to transfer more loads to the bordering bones due to their lower stiffness and higher energy absorption, which can help reduce stress shielding problems. In surrounding bones, the maximum VM stress occurs at the neck region from 5.42 MPa for pure titanium to 21.53 MPa for titanium foam with 80% porosity. Additionally, a porosity of 62.5% appears to be the most suitable since Young's modulus for this porosity (13.82 GPa) is close to the cortical bone's modulus (14.5 GPa). This suitability is shown in FEA by the similarity in stress level between pure titanium and the corresponding porosity. Overall, titanium foam implants appear to be a promising option for improving the effectiveness and longevity of bone implants in surgical dentistry. Conclusion: Systematic numerical studies on titanium foam dental implants with different porosities. Analysis of the FE results shows that titanium foam with a porosity of 62.5% is more beneficial for use in dental implants.

Porous Anisometric PNIPAM Microgels: Tailored Porous Structure and Thermal Response.

The porous structure of microgels significantly influences their properties and, thus, their suitability for various applications, in particular as building blocks for tissue scaffolds. Porosity is one of the crucial features for microgel-cell interactions and significantly increases the cells' accumulation and proliferation. Consequently, tailoring the porosity of microgels in an effortless way is important but still challenging, especially for nonspherical microgels. This work presents a straightforward procedure to fabricate complex-shaped poly(N-isopropyl acrylamide) (PNIPAM) microgels with tuned porous structures using the so-called cononsolvency effect during microgel polymerization. Therefore, the classical solvent in the reaction solution is exchanged from water to water-methanol mixtures in a stop-flow lithography process. For cylindrical microgels with a higher methanol content during fabrication, a greater degree of collapsing is observed, and their aspect ratio increases. Furthermore, the collapsing and swelling velocities change with the methanol content, indicating a modified porous structure, which is confirmed by electron microscopy micrographs. Furthermore, swelling patterns of the microgel variants occur during cooling, revealing their thermal response as a highly heterogeneous process. These results show a novel procedure to fabricate PNIPAM microgels of any elongated 2D shape with tailored porous structure and thermoresponsiveness by introducing the cononsolvency effect during stop-flow lithography polymerization.

A Methodology for the Rapid Qualification of Additively Manufactured Materials Based on Pore Defect Structures.

Additive manufacturing (AM) can create net or near-net-shaped components while simultaneously building the material microstructure, therefore closely coupling forming the material and shaping the part in contrast to traditional manufacturing with distinction between the two processes. While there are well-heralded benefits to AM, the widespread adoption of AM in fatigue-limited applications is hindered by defects such as porosity resulting from off-nominal process conditions. The vast number of AM process parameters and conditions make it challenging to capture variability in porosity that drives fatigue design allowables during qualification. Furthermore, geometric features such as overhangs and thin walls influence local heat conductivity and thereby impact local defects and microstructure. Consequently, qualifying AM material within parts in terms of material properties is not always a straightforward task. This article presents an approach for rapid qualification of AM fatigue-limited parts and includes three main aspects: (1) seeding pore defects of specific size, distribution, and morphology into AM specimens, (2) combining non-destructive and destructive techniques for material characterization and mechanical fatigue testing, and (3) conducting microstructure-based simulations of fatigue behavior resulting from specific pore defect and microstructure combinations. The proposed approach enables simulated data to be generated to validate and/or augment experimental fatigue data sets with the intent to reduce the number of tests needed and promote a more rapid route to AM material qualification. Additionally, this work suggests a closer coupling between material qualification and part certification for determining material properties at distinct regions within an AM part.