Adequate Resistance Research Articles

Genetic Characterization of Advance Bread Wheat Lines for Yield and Stripe Rust Resistance.

Wheat (Triticum aestivum L.) is a prominent grain crop. The goal of the current experiment was to examine the genetic potential of advanced bread wheat genotypes for yield and stripe rust resistance. Ninety-three bread wheat genotypes including three varieties (Kohat-2017, Pakistan-2013, and Morocco) were field tested in augmented design as observational nurseries at three locations (i.e., Kohat, Nowshera, and Peshawar) during the 2018-19 crop season. Various parameters related to yield and stripe rust resistance showed significant differences among genotypes for most of the characters with few exceptions. The analysis of variance revealed significant variations for all the genotypes for all the traits at all three sites with few exceptions where nonsignificant differences were noticed among genotypes. Averaged over three locations, genotypes exhibiting maximum desirable values for yield and yield components were KT-86 (325 tillers) for tillers m-2, KT-50 (2.86 g) for grain weight spike-1, KT-49 (41.6 g) for 1000-grain weight, KT-50 (74 grains) for grains spikes-1, KT-55 (4.76 g) for spike weight, and KT-36 and KT-072 (4586 kg ha-1) for grain yield. Correlation analysis revealed that grain yield had a significant positive correlation with grain spike-1 and grain weight spike-1 at Kohat, with grains spike-1, tillers m-2, and grain weight spike-1 at Nowshera, and with plant height, spike weight, 1000-grain weight, and tillers m-2 at Peshawar. Molecular marker data and host response in the field at the adult stage revealed that Yr15 and Yr10 are both still effective in providing adequate resistance to wheat against prevalent races of stripe rust. Four lines showing desirable lower average coefficient of infection (ACI) values without carrying Yr15 and Yr10 genes show the presence of unique/new resistance gene(s) in the genetic composition of these four lines. Genotype KT-072 (4586 kg ha-1 and 1.3 ACI), KT-07 (4416 kg ha-1 and 4.3 ACI), KT-10 (4346 kg ha-1 and 1.0 ACI), and KT-62 (4338 kg ha-1 and 2.7 ACI) showed maximum values for grain yield and low desirable ACI values, and these lines could be recommended for general cultivation after procedural requirements of variety release.

Impact of the manufacturing process on graphite blend electrodes with silicon nanoparticles for lithium-ion batteries

Correlating the input/output parameters of the manufacturing process aims to understand the link between the different steps of the Lithium-Ion Battery (LiB) electrode-making process. Fostering the interrelation of the properties in silicon/graphite blends for fabricating negative electrodes benefits the comprehension, quantification, and prediction of LiB output properties. Here, we report the impact of the manufacturing parameters during mixing, coating, and calendering on the properties of silicon/graphite blend negative electrodes. The mixing process was evaluated depending on the graphite content, where the viscosity increases with its percentage. Moreover, the slurry rheology directly impacts the electrode stability when the coating is done by using broader comma gaps. The calendering step evidences a porosity threshold necessary for adequate ionic resistance, tortuosity factor, and cycling life. Strong calendering increased the current collector adhesion, ionic resistance, tortuosity factor, and high cycling instability. On the other hand, better cyclabilities are obtained at moderate calendered electrodes, exhibiting the lowest ionic resistances and tortuosity factors.

Fracture Resistance and Crack Growth Mechanisms in Functionally Graded Ti–TiB

This paper presents the results of fracture tests and crack path observations for a layered functionally graded material (FGM) consisting of Ti and TiB phases. The composition varied in a nearly linear manner from a TiB-rich layer at the bottom to commercially pure (CP) Ti at the top. Elastic properties of the mixed phase interlayers were measured using nanoindentation testing, demonstrating a linear variation with composition. These results differ significantly from approximations calculated in previous studies using a non-linear rule-of-mixtures approach. Fracture tests were conducted on single edge notch bend [SEN(B)] specimens with the notch aligned orthogonal to the direction of the composition gradient. For this crack orientation, "average" R-curve behavior based on the J-integral was investigated to understand the mechanics of crack growth. The value of J was found to be minimal (less than 1 N/mm) below 47 pct volume fraction of TiB compared to a reported value of approximately 150 N/mm for pure Ti. These results indicate that a steeper transition to high concentrations of the metallic phase is necessary to achieve adequate fracture resistance in this metal/ceramic FGM. Observations on the specimen surface indicate crack path toughening mechanisms of this functionally graded material include crack bridging, branching, and deflection.

Selected Aspects of Transformation of Textile Elements of Firemen's Personal Protection

Aim: The purpose of the article is to present selected problems related to the directions of changes in the clothing that is the equipment of the rescuer firefighter and that is part of standard personal protective equipment. Introduction: Development in technology and the economy is resulting in products with increasingly complex structures in our environment. In the event of a fire, substances can be emitted that threaten the health and life of the firefighter. Therefore, personal protective equipment used by firefighters (including clothing) must be constantly adapted to the changing environment. Both the fibres and the structure or layering of the garment are modified. Increasingly, users of these products expect adequate resistance to biological and chemical agents. This is a result of the increasing number of factors that pose a risk when firefighters are working. Despite the clothing modifications used to date, it is still not possible to exclude the risk of toxic substanc- es, such as polyaromatic hydrocarbons, which are products of combustion in a fire environment, and acid gases penetrating the firefighter’s skin. The simultaneous exposure to radiant heat in the fire environment and the physical work performed by the firefighter significantly intensify the heat and mass exchange in the personal protection. Therefore, the interaction of protective structures with the rescuer’s body is playing an increasingly important role. Modifications based on nanotechnology are being used to make garments more resistant while maintaining or even reducing their weight. However, it should be pointed out that sometimes the changes concern one aspect, such as humidity, to the exclusion of other hazards arising from the physical and chemical characteristics of the substances emitted during the event. Methodology: The article is based on a review of selected literature on the topic covered. Conclusions: Modifications made to the fibres or to the structure and composition of the garment make it possible to obtain a product with improved performance in terms of protecting the firefighter. It is important to note, however, that they should consider all possible exposure pathways and not focus on one selected parameter. Therefore, further work is needed to adapt clothing to the emerging risks. Keywords: innovations, firefighter’s personal protective equipment, firefighter’s special clothing

Mechanical and Chemical Resistance of UV Coating Systems Prepared under Industrial Conditions.

In the upcoming years, it is expected that more furniture will be built from honeycomb panels due to the growing demand for lightweight, long-lasting furnishings. High-density fiberboard (HDF), previously used in the furniture industry as back walls in box furniture or drawer components, has become a popular facing material used in the production of honeycomb core panels. Varnishing the facing sheets of lightweight honeycomb core boards with the use of analog printing technology and UV lamps is a challenge for the industry. The aim of this study was to determine the effect of selected varnishing parameters on coating resistance by experimentally testing 48 coating variants. It was found that the interactions between the following variables were crucial in achieving adequate resistance: lamp power, the amounts of varnish applied, and the number of layers. The highest scratch, impact, and abrasion resistance values were observed for samples with optimal curing provided by more layers and maximum curing with 90 W/cm lamps. Based on the pareto chart, a model was generated that predicted the optimal settings for the highest scratch resistance. Resistance to cold liquids made with a colorimeter increases with lamp power.

Bushfire resistance of external light steel wall systems lined with fibre cement boards

Bushfires/wildfires have become a widespread and frequent occurrence in many parts of the world. With the adverse effects of climate change and the increasing population in the Bushland Urban Interface (BUI)/Wildland Urban Interface (WUI), ensuring adequate bushfire resistance of buildings in bushfire-prone areas has become very important. Improving the safety and integrity of the external building envelope is identified as a solution to minimise the bushfire related building damage and losses. This paper presents the details of bushfire resistance experiments conducted on external Light gauge Steel Framed (LSF) wall systems and the results. These LSF wall systems were externally lined with fibre cement boards and exposed to both bushfire radiant heat and flame zone fire conditions under indoor and outdoor test conditions. The results have shown that the rapid increment of the heat flux led to sudden explosive failure of the wall system whereas the gradual increment of the heat flux resulted in a progressive failure. This study has highlighted the importance of external cladding integrity and thermal shock resistance of building elements to enhance the bushfire resistance of buildings.

Physical Modeling for Thermal Proposal Validation (TES) in Lima Offices with Air Conditioning

Climate change adaptation measures are demanding the use of technologies that promote energy saving. The search for thermal comfort has encouraged the use of technologies such as the TES tank (Tank Energy System). This article presents the validation of the results obtained in the CFD simulation of a TES tank, through an evaluation of the model at 1/25 scale, to corroborate the thermal resistance of the tank whit thermal conductivity of 1.63 W/m. °K and expanded polystyrene with thermal conductivity of 0.036 W/m°K for both the walls and the lid. The circular TES tank designed guarantees, in addition to adequate thermal resistance, impermeability and durability so that it can function correctly during temperature measurements. In the model, the thermal resistance of the tank was corroborated, by obtaining an increase in the temperature of the temperature of the water in 8 hours of 7 °C (12.6 °F). That is, from 5.9 °C (42.62 °F) to 12.9 °C (55.22 °F), which does not exceed 15 °C (59 °F), the recommended value for its viability.

Experimental Investigation of Geopolymers for Application in High-Temperature and Geothermal Well Cementing

Summary With recurrent calls for a reduction in carbon emissions, geothermal (GT) energy has received increasing attention in recent years as a prominent source of clean energy. With current drilling technology, GT wells are being constructed in extremely challenging temperature environments, which could reach more than 600°F (315°C) in situ. However, GT well-cementing technology has not changed much over the past few decades, with ordinary Portland cement (OPC) still being the primary choice of cementing material. OPC has several drawbacks, including brittle behavior, shrinkage upon setting, poor bond strength to formation and casing, susceptibility to an acid gas attack, temperature-induced strength retrogression, and low tolerance toward drilling fluid contamination. These factors could lead to a poor cementing job, thus compromising well integrity and not ensuring proper zonal isolation for the life of the GT well. Thus, there is a need to develop an alternative material that is compatible with the GT environment and able to provide long-term zonal isolation. With a low carbon footprint, self-healing ability, and low shrinkage sensitivity, geopolymers or alkali-activated materials could be a suitable option to augment or even replace OPC. Some of the previous studies on geopolymers have shown that they could be a potential candidate for oil and gas well cementing and civil engineering applications, with some being stable at very high temperatures [up to 1,470°F (800°C)]. Geopolymers are formed by mixing an aluminosilicate source such as fly ash (FA) with an alkali-activating solution, such as sodium or potassium hydroxide or silicate. The aim of the study reported here is to demonstrate the applicability of geopolymers for GT well cementing. An experimental investigation was carried out to understand the behavior of geopolymer formulations made from FA, metakaolin (MK), and blast furnace slag in a high-temperature environment. The material properties such as porosity, viscosity, thickening/pump time, compressive strength, tensile strength, and bond strength were tested in the laboratory. It was found that geopolymer can be formulated to have the desired rheological properties with adequate pump time and resistance to drilling fluid contamination. In addition, the formulations can exceed the required compressive and tensile strength for GT cementing operations, while obtaining excellent bond strength values. These findings indicate that geopolymers are well-suited to provide long-term zonal isolation in high-temperature GT wells.

ÜÇ FARKLI POST SİSTEMİNİN AĞIZ İÇİNDE OLUŞABİLECEK KUVVETLERE KARŞI DAYANCININ İN VİTRO DEĞERLENDİRİLMESİ

Background: In order to ensure sufficient resistance against functional forces for dentin, which is severely weakened by excessive material loss in single-root single-canal teeth with previous root canal treatment, maximum retention and resistance must be the target. The main purpose of this study is to evaluate the shear rupture resistance of the chosen three kinds of posts placed in the teeth roots, against forces that could occur in the replicated mouth. Methods: Freshly extracted 45 teeth -maxillary canin and maxillary central- have been used in our study. Crown portion of the tooth was removed by cutting away 1 mm over the enamel cement junction. Root canals were obturated with a lateral condensation technique using AH-26 and gutta percha sealer. In the study, 15 specimens each from Flexi-Post, Cosmopost, and FRC Postec post systems have been placed in sockets opened down through teeth by using specific burs for each system. A dual cured composite cement (Variolink II low viscosity) was used to bind posts. Prepared specimens were put in steel hose by using acrylic resin. Standardized core material (Coradent) was applied onto top side of posts, and steel hoses were connected to Lloyd test instrument with an angle of 45 degrees. A force with a speed of 1 mm/min was applied to the specimens. Compression shear rupture values were recorded and One Way ANOVA and Kruskall-Wallis variance analyses were conducted for statistical evaluation. Results and Conclusion: Highest values were obtained in Flexi-Post group. FRC Postec was the second, and Cosmopost had the lowest strength values. However, all the systems provided adequate resistance against forces that could occur in the mouth, hence it was concluded that they can be utilized clinically. Key words: posts and cores, post system, prefabricated post systems

A silicon controlled rectifier with an anode Schottky contact

A three layer NPN- Silicon controlled rectifier (SCR) with an anode Schottky contact was simulated, fabricated and characterized. The high Schottky barrier of the anode contact increased the minority carrier injection and made the three layer SCR functional. The fabricated SCR had a maximal blocking voltage of 125 V, which is the voltage needed to deplete the high resistivity 525 μm substrate, having less than 1012 cm−3 carrier density. As expected from SCRs, at gain above one, the current reached its maximal value, which was limited by the measuring system. In order to reach adequate ON resistance, the Schottky contact needs to have a barrier height of ∼ 0.9 V, as for Pd/MoOx/n-Silicon or Platinum-Silicon contacts.

High stability polymer gel for lost circulation control when drilling in fractured oil and gas formations

When drilling in fractured oil and gas formations, drilling fluid loss is prevalent, and polymer gels are commonly utilized as lost circulation materials to plug fractures in loss zones. A high stability polymer gel was synthesized in this study employing acrylamide as the polymerizable monomer, a self-synthesized microsphere containing active ethylene groups as the cross-linker, laponite as both a flow pattern regulator and a physical filler, and ammonium persulfate as the initiator. This polymer gel's complex network structure considerably adds to its mechanical and thermal resilience, and its best gelation time is 12 h at 248°. Rheological properties of the gel were studied under various conditions. When the experimental temperature is 284°, the Na+ concentration is 100,000 ppm, or the Ca2+ concentration is 1000 ppm, the G′ and G″ of the polymer gel exceeded 1000 Pa and 200 Pa, suggesting that this gel has good thermal and salt stability. Contamination resistance studies reveal that the polymer gel has adequate contamination resistance for drilling fluid and formation water penetration, with G′ and G″ exceeding 1500 Pa and 400 Pa when the volume ratio of external fluids to gellant is 6:4. Furthermore, the density of the polymer gel may be adjusted to 2.0 g/cm3 by employing barite as a weighting agent, and the addition of the barite contributed to improving the structural stability of the gel due to the filling effect in the gel's network structure. Using fractured steel cores and a visible fracture model, the dynamic filling and plugging capabilities of this polymer gel in fractures were measured. When compared to frequently used polymer gellants, the high stability polymer gellant entirely fills the fracture area and exhibits a little gravity differentiation effect in large-scale fracture. After gel formation, it exhibits outstanding plugging capability for various fracture scales at 248°. Three successful field tests in the Tarim Basin, Xinjiang, China, demonstrated that the high stability polymer gel may be used to control lost circulation in fractured formations at high temperatures.

Pyramiding of Adult-Plant Resistance Genes Enhances All-Stage Resistance to Wheat Stripe Rust.

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most destructive diseases in wheat production. Pyramiding of adult-plant resistance (APR) genes is a promising strategy to increase durability of resistance. The stripe rust resistance (R) genes Yr18, Yr28, and Yr36 encode different protein families which confer partial resistance to a broad array of P. striiformis f. sp. tritici races. Here, we developed BC3F5 wheat lines representing all possible combinations of Yr18, Yr28, and Yr36 in a genetic background of the highly P. striiformis f. sp. tritici-susceptible wheat line SY95-71 that is widely used in stripe rust analysis. These lines enabled us to accurately evaluate these genes singly and in combination in a common genetic background. The adult plant resistance experiments were analyzed in the field, where stripe rust epidemics occurred frequently. The field results indicated that these partial R genes act additively in enhancing the levels of resistance, and a minimum of two-gene combinations can generate adequate stripe rust resistance. The Yr28 + Yr36 and Yr18 + Yr28 + Yr36 combinations also showed adequate resistance at the seedling stage, implying that APR gene pyramiding can achieve all-stage resistance. Meanwhile, the three genes were simultaneously introduced into elite wheat lines through gene-based marker selection. Elite lines exhibited strong all-stage resistance to stripe rust. This work provides valuable insights and resources for developing durable P. striiformis f. sp. tritici-resistant varieties and for elucidating the regulation mechanism of partial R gene pyramiding.

Self-excited asynchronous generator with PV array in detained autonomous generation systems

<span lang="EN-US">It's important to examine and handle the issue of green energy generation in inaccessible locations. Nonrenewable hybrid power has environmental and economic impacts. Reliable electricity and energy efficiency are priorities. Renewable energy that is eco-friendly and doesn't affect the environment. Solar and wind power, two ecologically benign and load-sharing-capable forms of renewable energy, are included in this technique. At the same time, solar power will keep the load voltage balanced and the system stable thanks to the inclusion of a DC-DC converter. The asynchronous generator has been selected because of its low maintenance needs and extended service life; nevertheless, the voltage on the load side is unbalanced when this machine is in operation. An asynchronous generator can be a viable alternative to well-developed synchronous generators for use in wind turbines or small hydro generators because they have relatively inexpensive costs, are simple, require inadequate maintenance, possess adequate resistance to wear and tear, and have reduced overload damage. It is difficult to maintain a continuous supply of energy in faraway regions because of the lack of related work in the power distribution networks. This problem is addressed in this paper by a well-designed converter that maintains a constant output voltage.</span>

‘Thermo-mechanical behavior of alternative material combinations for full-arch implant-supported hybrid prostheses with short cantilevers’

ObjectivesTo compare the fracture resistance (FR) of three combinations of materials for full-arch maxillary implant-supported hybrid prostheses (HPs) with short cantilevers (≤ 10 mm). MethodsMaxillary HPs were fabricated and classified as follows (n = 5 each): Group-1 (CC-A, control): acrylic-resin-veneered Co-Cr frameworks; Group-2 (CF-A): acrylic-resin-veneered carbon-fiber mesostructures; and Group-3 (CF-R): composite-resin-veneered carbon-fiber frames. Specimens were thermal-cycled (5,000 cycles; 5 °C–55 °C; dwell time: 30 s). Vertical loads were applied until failure, first at the 10-mm-long cantilever (LC), and, afterwards, at the anterior region (AR), using a universal testing machine (crosshead speed: 0.05 mm/s). The fracture pattern was assessed by stereomicroscope and SEM. The one-way ANOVA, the Bonferroni, and the independent samples t tests, were run (α= 0.05). ResultsAt LC, CF-A, and CC-A samples exhibited the highest FR values (p< 0.001), showing no differences to each other. At AR, CC-A specimens recorded the highest FR, followed by CF-A samples (p< 0.001). CF-R HPs displayed the lowest FR at both locations (p< 0.001). The only group with differences between the tested sites was the CC-A, the AR being more resistant (p< 0.001). Most CC-A and CF-A HPs failed cohesively. CF-R prostheses mainly failed adhesively. ConclusionsMaxillary HPs with short cantilevers (≤ 10 mm) made of Co-Cr or carbon-fiber veneered with acrylic resin demonstrated an adequate mechanical resistance (> 900 N). Clinical significanceFor maxillary HPs with cantilevers up to 10 mm, acrylic-veneered carbon- fiber mesostructures may be recommended, whereas coating carbon-fiber frames with composite resin seems not suitable.

Static Analysis and Design of Innovative Porous Lumbar Interbody Cages

Background: Interbody discs play a major role in maintaining the spine and skeleton structures which may undergo damage. If damage is so severe that the disc cannot be repaired, implants, known as “interbody cages”, should be used. Objectives: The present study aimed to propose a novel design with proper strength and resistance against axial disc torques. Methods: The design and analysis of innovative anatomical cages comprised two stages, namely, cage design according to three different models and finite element analysis (FEA). The designs were based on the spine of a 15-year-old teenager without lumbar disc disease. To model the vertebrae, computed tomography )CT( scans and Digital Imaging and Communications in Medicine (DICOM) files were entered into Mimics Version 10.01 (Materialise Inc., Leuven, Belgium); then, the L4 and L5 spinal segments were modeled. Results: The implants were fixed to the bottom level and subjected to a net force of 1000 N. Additionally, a moment load of 7.5 Nm in flexion, extension, axial rotation, and lateral bending was applied in these three cage models. Considering the application of 1000-N force, maximum and minimum stress and strain distribution rates were presented in three honeycomb, Islamic architecture, and porous gyroid cages. Conclusion: Novel designs for lumbar cages were considered to achieve damping capacity, light weight, and high resistance. Considering the characteristics of the honeycomb, Islamic architecture, and gyroid structures, optimal designs were proposed for lumbar cages to achieve adequate strength and resistance against axial disc torques under normal conditions.

Design of Exercise Device for Older Adults

Older adults should perform physical activity to improve cardiorespiratory functions. Aerobic exercises improve cardiovascular function, decrease basal heart rate and blood pressure, and improve mood and energy. To facilitate the execution of aerobic physical activity in older adults, the objective of this research was to design an exercise device for older adults. Starting from design specifications such as comfort, size, weight, resistance, and cost, we developed the detailed design of a horizontal bicycle. The designed device, thanks to its horizontally disposed structure, its adequate resistance to pedaling, its dimensioning based on anthropometric measurements of the Chilean population, and the disposition of sensors for heart rate and oxygen saturation, is suitable for older adults. Its weight and size also make it convenient for use inside the home, and the use of materials, components, and manufacturing processes available nationally and within the cheapest options, increases the possibility of access by older adults.

Evaluation of wheat stem sawfly‐resistant solid stem Qss.msub‐3BL alleles in hard red winter wheat

AbstractHost plant resistance provided by solid stems has been the most effective means for mitigating wheat stem sawfly (WSS) (Cephus cinctus Norton) damage in spring and winter wheat (Triticum aestivum L.). The solid stem trait originates from the spring wheat cultivar “Rescue” and is associated with a quantitative trait locus allele Qss.msub‐3BL.b that explains the majority of the variation for stem solidness. Recently, a new Qss.msub‐3BL solid stem allele, designated Qss.msub‐3BL.c, was identified in the spring wheat cultivar “Conan”. It produces a solid stem phenotype early in plant development but dissipates during plant growth. The Qss.msub‐3BL.c allele provides effective WSS resistance in spring wheat but has not been tested in winter wheat. To examine if the Qss.msub‐3BL.c allele provides adequate WSS resistance in winter wheat, near‐isogenic lines (NILs) were developed using marker‐assisted backcrossing. This enabled comparisons between the hollow stem Qss.msub‐3BL.a, solid stem Qss.msub‐3BL.b and solid stem Qss.msub‐3BL.c alleles for stem solidness, WSS resistance, and agronomic traits in Montana growing environments. Compared to the hollow stem allele, the NILs with the Qss.msub‐3BL.c allele increased stem solidness and reduced WSS stem cutting. However, the Qss.msub‐3BL.c allele resulted in lower solid stem scores and greater WSS stem cutting compared to the Qss.msub‐3BL.b allele. Overall, these findings indicate that the Qss.msub‐3BL.c allele failed to provide sufficient WSS resistance in the winter wheat backgrounds tested in this study.

Reliability-Based Fire Resistance Periods for Buildings in England

The traditional route to achieving adequate structural performance in the event of fire is through ensuring that structural elements attain fire resistance ratings. The magnitude of these ratings typically varies in function of the building use, size, and height. In their genesis, fire resistance ratings were a proxy for the specification required of elements such that they had a reasonable likelihood of surviving the full duration of a fire, i.e., burn-out. As such, fire resistance periods were specified in the function of fire load, which, over time, progressively increased in consideration of the consequences of fire induced structural failure. This ratcheting of fire resistance periods was seemingly done so based on the collective experience of the profession, in response to observations from real fires and, where applicable, resulting disasters. That is, the safety levels associated with current fire resistance recommendations in most global codes and guidance documents are not determined. Therefore, this paper presents a review of reliability-based acceptance criteria for structures, ahead of their application, to determine fire resistance recommendations for buildings in England based on both codified reliability indices and the principle of relative (marginal) lifesaving costs. The study applies a novel form of probabilistic time equivalence, which is augmented by fire occurrence related statistics/parameters, to arrive at risk-informed fire resistance ratings that directly relate to the life safety consequences of fire induced structural failure (i.e., fatalities) to adequate fire resistance ratings. In determining these building fire resistance periods, it is observed that safety targets which implicitly include material damage and building reconstruction costs result in fire resistance recommendations that are well-aligned with National codes and standards. That is, to some extent, the ratcheting of fire resistance periods with time has resulted in some potential resilience to fire. Where safety targets are rationalised in consideration of life safety only, i.e., through the principle of relative (marginal) lifesaving costs, it is shown that fire resistance periods can be optimised, particularly in sprinkler protected buildings. However, this has the potential to introduce vulnerabilities to common mode failures.

Fracture toughness of 3D printed denture teeth.

Advances in digital dentistry lead to use of three-dimensional (3D) printed resin denture teeth. Fracture toughness of these teeth must be assessed. This study aimed to compare the chipping and indirect tensile fracture resistance of denture teeth fabricated by 3D printing technique with traditionally fabricated resin denture teeth. Four groups (Gr) were made (n= 50/group): Gr-1 3D printed denture teeth (denture teeth; Formlabs Inc., Somerville, MA, USA), Gr-2 SR-Orthosit-PE (Ivoclar Vivadent AG), Gr-3 Portrait IPN (Dentsply Sirona), Gr-4 Pala Premium 8 (Heraeus Kulzer GmbH). Stereolithography 3D printing was used to create the methacrylate-based photopolymerized resin teeth models and remaining group teeth were collected commercially. A 1 mm/min chipping and indirect tensile fracture speed tests were carried out till fracture occurred. The data so obtained were statistically analysed using one-way analysis of variance with Tukey's honestly significant difference multiple comparisons test (p< 0.05). At the end of the test, the fractured areas of the specimens were evaluated by the chief researcher to assess the fracture pattern of the teeth. The indirect tensile fracture values of the 3D printed teeth were more than that of Pala Premium-8 and SR-Orthosit-PE but it was lower than that of Portrait IPN teeth. In chipping test, buccal chipping of the loaded cusp was seen in 3D printed resin without distortion and in indirect tensile test in 3D printed resin teeth, line of fracture emerges near the loading point propagates from the inner incline of both cusps and extends cervically, unlike in other groups where first deformation occurs then fracture. Prosthetic teeth fabricated by the 3D printing technique using printable resin material provide adequate fracture resistance as denture teeth.

A review on the production of 17-4PH parts using press and sinter technology.

The press and sinter method remains the standard among powder metallurgy processes for powdered stainless-steel materials. It delivers low cost, low oxidation rate, and adequate corrosion resistance. Furthermore, 17-4PH is a martensitic stainless-steel that is commonly used for high-strength and medium-ductility stainless steel parts. However, a few studies have investigated the press and sinter method for producing 17-4PH parts. This shortage is due to the high hardness (low compressibility) of 17-4PH powder. Thus, the main objective of this study is to evaluate the press and sinter method in terms of the manufacturing process, the influencing factors, and the theoretical basis of press and sinter methods in conjunction with metal injection molding technology for the production of 17-4PH parts. First, the literature and monographs are examined and summarized to cover the previous results, research progress, development trends, and applications of press and sinter method 17-4PH parts. Following the theoretical analysis, the practical investigation was conducted by producing parts with cold pressing from 800 to 1600 MPa, followed by sintering: the sintering temperature was 1200 °C for one hour under a protective vacuum atmosphere. ImageJ analysis was performed to measure the sinter density. The results showed an increase in relative sinter density from 84.43% to 96.43% for 800 and 1600 MPa, respectively, while the earlier results reached 93.47%. Overall, the press and sinter method enables the production of high-hardness 17-4PH parts with a high density, without using additives like lubricants, wax, or alloying elements.