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Breast cancer remains a leading global cause of morbidity and mortality. While the field of immunotherapy is a promising avenue of investigation and has revolutionized the standard of care for melanoma and lung cancer, modest response rates and a high incidence of immune-related adverse events often necessitate the administration of a sub-therapeutic dose or treatment cessation. Injectable and implantable drug delivery devices present a novel strategy to achieve sustained delivery of potent concentrations of drug directly to the tumor site and minimize systemic toxicity. This review will address the current limitations with conventional immunotherapy for breast cancer treatment, and the recent developments and future prospects in localized delivery strategies. We describe implantable scaffolds and injectable biomaterials for the localized delivery of immunotherapy, which can improve the safety and efficacy of immunotherapies. We discuss the limitations of these delivery systems, such as the influence of shape and material type on drug release and tumor uptake. The challenges of clinical translation, such as the availability of appropriate preclinical animal models and accurate reporting is also discussed. Considerations of these issues will pave the way for effective new therapies that will improve treatment response, patient survival and quality of life for breast cancer patients.

The onset and evolution of soil arching in a trapdoor apparatus was investigated using discrete-element modelling (DEM). The effects of wall friction, particle size and material type (sand and rubber–sand) on the micro-behaviour of the granular material during arching was monitored. It was observed that when the particles are large with respect to the trapdoor width, they form a stable arch over the trapdoor element. An ‘intermediate zone’ within the granular materials is then introduced. This is the zone where inter-particle contact forces increase in the early stage of active arching and then decrease as the trapdoor displacement continues. The DEM simulation results showed that the granular particles rearranged in reaction to arching, causing uneven densities throughout the backfills. The distributions of two-dimensional stresses in the cross-section of the modelled sand and rubber–sand backfills were obtained using the kriging method and compared.

Statement of problem: New polyvinyl siloxane (PVS) materials with enhanced properties have been developed to improve and facilitate implant impression techniques. However, studies on their accuracy are lacking. Purpose: The purpose of this in vitro study was to determine the accuracy and precision of implant impressions made with some recently introduced materials on a simulated patient requiring an all-on-4 implant-supported prosthesis. Well-established polyether materials were also evaluated as a comparison. The variables considered were material type, consistency, splinting or not splinting techniques, and implant angulation. Material and methods: A reference master model was made by inserting 4 implants at angles of 0, 5, and 10 degrees. Eighty impressions were made at 37 °C in wet conditions by using a standardized technique. Eight groups (n=10) were created using monophasic, single-viscosity materials (Hydrorise Implant Medium, HIM-ns; Hydrorise Implant Medium, HIM; Honigum Mono, HM; Impregum, IMP), and 2-viscosity materials (Hydrorise Implant Heavy+Light-ns, HIH+L-ns; Hydrorise Implant Heavy+Light, HIH+L; Honigum Heavy+Light, HH+L; and Permadyne and Garant [Heavy+Light, PeH+L]). Hydrorise materials were used with splinting and not splinting (ns) techniques. The reference points located on the connecting platforms of the transfer copings (TCP) were compared with the same points on the implant connecting platforms (ICP) located in the reference model. The accuracy and precision of the impressions were determined as linear 3D errors and standard deviation between each TCP-ICP couple by using an optical coordinate measuring machine (OCMM). Results: PVS materials were generally better than polyether materials, with Hydrorise materials (HIM and HIH+L) showing significantly better accuracy and precision (30.9 ±14.4 μm and 28.7 ±15.5 μm, respectively) than IMP and PeH+L polyethers (44.2 ±16 μm and 43.8 ±17.6 μm, respectively; P

OBJECTIVE The objective was to provide a comprehensive overview of color interactions between resin composite (RC) and its surroundings, analyze the design and results of respective research studies, and provide clinical and research recommendations. OVERVIEW Resin composite (RC) materials can adjust their color to that of surrounding enamel and dentin to a different extent. This phenomenon has been referred to as the "chameleon effect" in dental jargon, while color blending/adjustment/shifting/assimilation is more scientific terms. Studies that evaluated the color adjustment potential of RCs have employed different methods. This article discusses the (a) terminology used to describe color adjustment potential, (b) color science theories associated with color adjustment, (c) design of respective studies, including methods, specimens, and calculations, and (d) their outcome and reported results. Clinical implications and future directions related to the color adjustment potential of RCs are also provided. CONCLUSIONS Factors that influence the color adjustment potential of RCs are classified into three categories: (1) material type, (2) cavity design, and (3) the substrate surrounding the restoration. Each factor can be optimized to enhance color matching and the restorative outcome. CLINICAL SIGNIFICANCE A material that blends well and exhibits pronounced color adjustment potential would likely improve the color match and therefore the esthetic outcome. These materials "work" for dental professionals by compensating for their suboptimal shade matching and/or lack of an excellent match in the used material. This review aims to further the understanding of the inherent properties of RCs and allow clinicians to fully utilize them to place RC restorations and minimize the time spent on modifying or replacing existing ones. Hence, the outcomes would encompass the increased chairside efficiency, enhanced esthetic outcome, and patient satisfaction.

This paper addresses the optimisation of mineral value chains under metal and material type uncertainty. A mathematical model to simultaneously optimise the extraction decisions and the destination...

The obstacle faced during the fatigue test is the waiting time which is quite long and inefficient, especially for test specimens made of ductile metal with waiting times of up to several days. The research method includes reducing the specimen radius to obtain a flexural stress approaching 400 MPa which was originally 229 MPa from a radius of 254 mm to 240 mm with the results of turning the original specimen obtained a minimum diameter of 8.6 mm is reduced to 7.3 mm at a maximum loading of 10 kg. Results of the research are brass specimens C3604BD type with a minimum diameter of 8.6 mm at a flexural stress of 298 MPa showing a fatigue life of 2455546 cycles with a test duration of 1754 minutes and a minimum specimen diameter of 7.3 mm at a flexural stress of 299 MPa showing a fatigue life of 684311 cycles with a test duration of 489 minutes which means that with a minimum specimen diameter of 7.3 mm the fatigue life is 3.59 times shorter than a minimum specimen diameter of 8.6 mm. Meanwhile, for aluminium AA1101 type with a minimum specimen diameter of 7.3 mm at a flexural stress of 182 MPa, the fatigue life is 422117 cycles with a test duration of 278 minutes and with a minimum specimen diameter of 8.6 mm at a flexural stress of 183 MPa, the fatigue life is 389232 cycles with a test duration of 302 minutes which means that with a minimum specimen diameter of 7.3 mm the fatigue life is 1.05 times shorter than the minimum specimen diameter of 8.6 mm or almost the same.

Objective To compare the translucency and masking of zirconia-reinforced lithium silicate with lithium disilicate glass-ceramic and hybrid composite. Materials and methods One hundred and twenty disc-shaped specimens were fabricated using Enamic, Celtra Duo, IPS E.max CAD, and Suprinity. Twelve groups were prepared according to material type and thickness (0.5, 1.0, and 1.5 mm). The specimens were tested over five substrates: composite resin-A3.5 shade (A3.5 control group), zirconia-A1 shade (ZR), nickel–chromium alloy (NC), black (B), and white (W). A spectrophotometer operating at wavelengths from 360 to 750 nm and a view-area size of 9.53 mm was used for color measurement. Results Mean color difference values (ΔE) were found to be lowest in Suprinity and highest in IPS E.max. CAD. Color difference values were significantly related to substrate shade. The A3.5 substrate revealed the significantly lowest ΔE values of all the substrates (P = 0.05). Regarding the translucency parameters for ceramics of different thicknesses, a significant difference was observed among all groups except in Suprinity. Conclusions Different ceramic types with different thicknesses and substrate strongly affect translucency and masking. Clinical significance Fabricating durable aesthetic restorations that also meets patients’ expectations is among the most significant challenges in dentistry. With high demand for more natural restorations, ceramics based on computer-aided design (CAD) and computer-aided manufacture (CAM) became popular and exhibited excellent results. However, various factors such as abutment shade, luting cement color, and ceramic type, thickness, and translucency may affect the prosthesis shade. The objective of this study was to evaluate the effects of these factors on the final shades of CAD/CAM-based ceramic restorations.

In order to design effective shredding machines dedicated to shredding wood-based waste, information about the mechanical properties of materials subjected to shredding is necessary. A number of mechanical properties of particleboard, oriented strand boards, and medium-density fibreboards in the aspect of shredding process have been experimentally determined in the article. The influence of material type, blade geometries, and cutting depth on cutting force and elasticity coefficient were analysed. Blade geometries reflect different phases of rotation of the cylindrical wood chipper’s knife. It has been shown that a knife with the most favourable geometry is characterized by the lowest values of the stiffness coefficient for each of the materials. This is the geometry of the cylindrical wood chipper’s knife exactly halfway into the cutting process. By contrast, the least favourable geometry is characterized by a knife corresponding to the beginning of the cutting process. Among the tested materials, the medium density board requires the most energy to change its structure, and the laminated particleboard requires the least. The presented results can be a set of input data necessary to model the work required to implement the cutting process, but also enable validation of existing cutting models.

Reasons for failures of bilayer yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) restorations include the core-veneer interface bond strength. The influence of the veneering method on the bond strength of veneered Y-TZP is unclear.The purpose of this systematic review and meta-analysis was to evaluate the effect of the veneering method on the bond strength of bilayer Y-TZP.This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Searches were performed on PubMed/MEDLINE, Web of Science (Core Collection), and Scopus for in vitro studies evaluating the effect of the veneering technique on the bond strength of bilayer Y-TZP. Statistical analyses were performed with random-effect models (α=.05).From 619 identified studies, 140 were selected for full-text analysis and 16 were included. Manual searching yielded no additional articles. The meta-analyses comprised 15 studies, and 1 study was included only in the descriptive analysis. Meta-analyses compared the hand-layered method (control) with pressed, fused, and cemented veneering methods. The fused and cemented techniques were analyzed by using subgroups assessing the veneering ceramic type (predominantly glass-ceramics and particle-filled glass-ceramics). Similar bond strength results (P=.540) were found for pressed and hand-layered veneered Y-TZP specimens. Fused veneers achieved higher bond strength values (P.001) than the hand-layered veneers on Y-TZP frameworks, irrespective of the veneering ceramic type (predominantly glass-ceramics: P=.002; particle-filled glass-ceramics: P.001). Global and subgroup analyses indicated that lower core-veneer bond strength values (P.001) were found for cemented in relation to hand-layered veneers.Core-veneer interfacial adhesion was equivalent for pressed and hand-layered veneering techniques. Improved bond strength, regardless of the veneer ceramic material type, was achieved by the fused veneering method, which seems to be a promising choice for the veneering of Y-TZP. In contrast, the cemented method may be unsuitable for veneering Y-TZP structures because of its lower bond strength than the hand-layered veneering technique.

Welding is one of the metal joining processes in manufacturing. CDFW (continuous drive friction welding) is a welding process to join two workpieces by applying pressure at one end of the object and rotating another one where the friction action applies at interface. The purpose of this study is to study temperature distribution on the surface of the welding area and the heat-affected zone represented by a fully plasticized zone (Zpl) and to get an insight of a friction welding process. The variables of CDFW used were double chamfer angle, upset pressure, and burn off length. The initial area of friction was equal that is at a diameter of 14 mm. The method of modeling the CDFW friction welding is via computer simulations using ANSYS 18.1 software. This research uses aluminum material type Al6061. The Taguchi method was applied in designing the simulations. In this modeling, the model with the double chamfer of 15 °, the upset pressure of 120 MPa, and the burn-off length of 9 mm has a small ZPl area of 10.256 mm2. Whilst the specimen model, with a double chamfer angle of 45 °, the upset pressure of 240 MPa, and the burn-off length of 7 mm has a large Zpl area of 56.55mm2. The area of a narrow fully plasticized area caused by small chamfer angle and an upset pressure of 240 MPa. The area of fully plasticized zone shows how much material can be integrated during the friction welding process and how much strength of the weld metal. The model with the chamfer angle of 15 º, the upset pressure of 240 MPa, and the burn-off length of 9 mm has the widest temperature distribution and the highest maximum temperature. Meanwhile, the model with the chamfer angle of 30º, the upset pressure of 120 MPa, and the burn-off length of 9 mm has the narrowest temperature distribution and the lowest maximum temperature. The smaller chamfer angle increased upset pressure and burn-off length result in the wider temperature distribution, higher maximum temperature, and smaller Zpl.

Background Endodontic surgical procedures, when performed, require retrograde filling materials that are biocompatible, non-toxic, non-irritant, dimensionally stable, and ideally promote bone formation. Precise evaluation of retrograde filling materials in clinical trials is necessary to give holistic view for properties of material and potential outcome from its use. The purpose of this review is to evaluate the effect of retrograde material type and surgical techniques on the success rate of surgical endodontic retreatment. Methods An electronic search was performed in the time frame between 1st of January 2000 to 1st of September 2020 using database. Sources Web of Science, PubMed and redundant hand searches through their references. Seven inclusion–exclusion criteria were set for the selection and identification of relevant articles. Risk of bias was conducted for the included studies. Results Nine randomized clinical trials (RCTs) fulfilled the inclusion criteria for this systematic review. The outcome of this review revealed that none of the reviewed trials totally-fulfilled CONSORT 2010 criteria. Conclusions In light of the outcome of this review, there is no enough evidence to support the superiority of certain retrograde filling material or surgical technique over another in the success rate of surgical endodontics retreatment. The variety of methodologies and strategies, such as patient selection, the method of treatment and study analysis, led to doubtful credibility of the obtained clinical evidence. Further prospective randomized controlled clinical trials evaluating the specific effect of the various used materials are needed.

Purpose: Assess the effect of material selection as well as different fabrication techniques of metal ceramic (MC) and all ceramic crowns on their clinical outcomes, marginal and internal fit. Materials and methods: In vivo study(I); twenty- eight patients were provided with twenty-eight crowns restoring mandibular first molar tooth. Patients were distributed into 2 groups and 2 subgroups according to different materials and fabrication techniques: fourteen patients received MC crowns, group (I); seven patients received crowns with conventional casting of Co-Cr copings, subgroup (A) and seven patients received crowns with direct milling of Co-Cr copings, subgroup (B). Fourteen patients received IPS e.max press crowns, group (II); seven patients received crowns with conventional wax pattern, subgroup (A) and seven patients received crowns with 3D printing resin pattern, subgroup (B). The survival rate of these crowns was evaluated and statistically analyzed. In vitro study(II); one machined die was prepared to simulate crown preparation of mandibular first molar tooth. 60 crowns were constructed on die and divided into 2 groups (30 samples each) and 2 subgroups (15 samples each) according to different materials and fabrication techniques similar to in vivo study. Replica technique obtained to measure marginal and internal fit using Digital microscope. Results: The survival rate of MC and press crowns was 98% and 60% respectively. Press crowns and digital technique showed superior marginal and internal fit than MC crowns and conventional technique respectively. Conclusions: Material type and fabrication technique of MC and all ceramic crowns influence their clinical outcome, marginal and internal fit.

The spot welding procedure is used in a variety of industrial applications. The most critical elements influencing welding quality, productivity, and cost are the spot welding parameters. This research examines the effect of welding factors such as welding current and welding time on the strength of various welding joint designs. Resistance spot welding (RSW) is used in the automotive industry for manufacturing. This research focused on the optimization of process parameters for resistance spot welding (RSW), as well as the tensile testing and spot weld diameter. The goals of this analysis are to comprehend the physics of the process and to demonstrate the effect of electrical current, weld time, and material type on the resistance spot welding process.

OBJECTIVE To analyze translucency variations among four different contemporary esthetic ceramic systems having different shades and thicknesses. MATERIAL AND METHODS Ceramic specimens having different shades and translucencies were tested: leucite reinforced glass-ceramic (ECAD), conventional feldspathic ceramic (Noritake), zirconia reinforced lithium silicate glass-ceramic (Suprinity) and hybrid ceramic (Enamic). Specimens of 0.6, 0.9, 1.2, 1.5 and 2.0-mm thickness (n = 3/group, 615 total) were prepared. Translucency (TP) and Relative Translucency (RTP) Parameters were calculated from spectroradiometric color readings. Effects of shade and thickness for a given system were statistically analyzed using MANOVA and Tukey post-hoc multiple comparisons tests. Translucency variations were assessed comparatively with literature-based perceptibility and acceptability thresholds. RESULTS TP/RTP values of all ceramic materials decreased with increasing thickness. The most translucent specimens were 0.6-mm thick ECAD HT-A3.5 (TP = 31.99) and ECAD HT-C2 (RTP = 23.75), while the least translucent was 2-mm thick Enamic T-3 M2 (TP = 7.27; RTP = 4.79). Thickness and material type significantly influenced translucency (p

An experimental study is conducted to show the influence of the tubes material type of the heat exchanger on the refrigeration system performance. The system is operated by using R134a as a working fluid, 2 mm internal diameter, and different lengths of capillary tubes which were 120, 135, and 150 cm. The experimental results showed that when increasing the refrigerant mass flowrates led to reducing each of the performance coefficient COP, number of transfer unit NTU and evaporator effectiveness ε. However, the highest improvement had appeared for each parameter COP, NTU, and ε which were 21%, 113.38%, and 59.42% respectively at a capillary tube length of 120 cm and [Formula: see text] = 3.19 g/s compared to the length of capillary tube 150 cm. Besides, it was found an increase in [Formula: see text] with the incrementing in the capillary tube length from 120 cm to 150 cm. The biggest percentage of compression power was 23% at the capillary tube length of 150 cm compared to others at [Formula: see text] = 3.71 g/s. Finally, the experimental results of COP and [Formula: see text] were validated by comparing them with other publications.

Biofilms in industrial cooling tower systems are an important problem. The importance of the surface material in the response to an oxidising biocide (chloramine T trihydrate) was substantiated in our study. Polyvinyl chloride (PVC) cooling tower fill material, stainless steel cooling tower construction material and glass surfaces were compared by evaluating the bacterial loads on materials before and after biocidal treatment. The greatest logarithmic decrease in bacterial load was recorded as >3 log for glass after the first two months and for PVC after the second month. Actively respiring bacterial counts and adenosine triphosphate (ATP) measurements showed that there was no significant difference in the sensitivity of biofilm-associated cells to the biocide on the different surfaces. In addition, the effect of the biocidal treatment decreased with increasing biofilm age, regardless of the material.

Background Lumbar spine fusion surgery is traditionally performed with rigid fixation. Because the rigidity is often supraphysiologic, semirigid rods were developed. To the best of our knowledge, a comprehensive evaluation of rod material type on surgical outcomes has yet to be conducted. Methods A systematic review based on PRISMA guidelines was conducted across 3 electronic databases. After examination for inclusion and exclusion criteria, data were extracted from the studies. Results Seventeen studies, including 1399 patients, were included in this review. The mean rigid rod fusion rate is 92.2% and 95.5% for semirigid rods (P = 0.129). The mean improvement in back pain was 60.6% in rigid rods and 71.6% in semirigid rods. The improvement in leg pain was 81.9% and 77.2%, respectively. There were no differences in visual analog scale back pain score (P = 0.098), visual analog scale leg pain score (P = 0.136), or in functional improvement between rigid and semirigid rods (P = 0.143). There was no difference (P = 0.209) in the reoperation rate between rigid rods (13.1%) and semirigid rods (6.5%). There was a comparable incidence of adjacent segment disease (3%), screw fracture (1.7%), and wound infection (1.9%) between rod material types. Conclusions There is a moderate level of evidence supporting that surgical intervention results in high fusion rates regardless of rod material type. Surgical intervention improves back pain, leg pain, and function, with neither material type showing clear superiority. There are comparable rates of reoperation, development of adjacent segment disease, development of mechanical complications, and incidence of infection in both rigid and semirigid rods. Further studies regarding rod material type are warranted.

The overall objective of this work was to develop a simple and effective passive sampling protocol for the detection of SARS-CoV-2 in sewer catchments at targeted institutional-level sampling sites in a region of low COVID-19 prevalence. We developed a new 3D-printed sampling cage and assessed four commercially-available materials (cotton gauze, cotton cheesecloth, cellulose sponges, and electronegative filters) for RNA adsorption in the cage. We determined that cheesecloth and electronegative filters provided an effective approach for collecting and measuring SARS-CoV-2 in wastewater. We also compared the performance of three elution mixtures (a commercially-available lysis buffer, a Tween®20-based buffer, and a 1:1 acetonitrile:water mixture) for detection of heat-inactivated SARS-CoV-2 reference material (HI-SCV-2) spiked into municipal wastewater at 1.0 × 103 genomic units per millilitre (GU mL−1). The highest mean RNA concentrations were achieved using the cheesecloth (7.0 × 104 ± 3.7 × 104 GU per eluate) and electronegative filters (2.3 × 104 ± 2.5 × 104 GU per eluate) in combination with the Tween®20-based buffer with positive detections in all three biological replicates for both material types. We deployed passive samplers at two sewer catchments (locations A and B) to compare the performance of each passive sampler material type in the field. Over 15 sampling events at each site, we demonstrated that both cheesecloth (location A) and electronegative filters (location B) coupled with a Tween®20-based elution technique could be utilized for the reliable detection of SARS-CoV-2. These results have demonstrated a quick and effective passive sampling approach for SARS-CoV-2 detection in targeted locations in wastewater collection systems, which may have long-term applicability as global vaccination programs evolve.

The application of FDM technique for prototyping purposes in the industries such as aerospace and medicine has brought to attention the importance of dimensional accuracy of the manufactured models. The dimensional accuracy of FDM printed parts depends on various process parameters including layer thickness, raster width, infill pattern, etc. that influence the overall part accuracy. The purpose of this study is to make a comprehensive review of publications that investigated the effect of process parameters on the dimensional accuracy of FDM printed parts in order to understand the individual effect of each process parameter as well as to find out the optimal levels of each parameter according to the types of material. Overall 31 articles that investigated the influence of three process parameters, namely layer thickness, extrusion temperature, and part orientation were reviewed and summarized in terms of the material types that were used such as ABS, PLA, and other resins. The main findings indicating the optimal level of process parameters and the methodology of each article was summarized in the tables. The current results of the research found that the layer thickness values between 0.1 mm and 0.2 mm are preferable for ABS and PLA parts, whereas ASA and Nylon parts tend to be accurate with higher layer thickness values. Low values of extrusion temperature are found to be preferable, this parameter is also less dependent on material type. In terms of part orientation, 0° and 90° are found to be optimal levels for ABS and PLA printed parts, respectively. In addition, the optimal level of each process parameter is likely to vary with secondary factors such as the geometry of the part, resin type, and the different dimensions of the part. Therefore, it was concluded that in understanding the effect of each process parameter on the dimensional accuracy of FDM printed parts, the influence of secondary factors should also be considered and investigated.

HighlightsA model was developed to express soil-metal sliding resistance in terms of normal stress and sliding path length.Soil-metal sliding resistance data, different from those used to develop the model, were acceptably simulated.The model is expected to be useful in the design and development of soil-engaging equipment.Abstract. Most previous soil-material sliding resistance studies have focused on the measurement and formulation of only qualitative relationships between sliding resistance and the material type, applied normal stress, sliding path length, and/or soil-properties. Few studies have attempted to formulate quantitative mathematical relationships between soil-material sliding resistance and these factors, or to mathematically express the relative contributions of the frictional and adhesive components to the total sliding resistance. In this study, a mathematical model was developed to express the components of soil-metal sliding resistance for a clay soil as functions of applied normal stress and sliding path length. The model is restricted to soil containing enough moisture to exhibit cohesive strength, but not so much moisture to exhibit gross plastic behavior. Soil-metal sliding resistance data, different from those used to develop the model, were acceptably simulated, as the mean square error between the simulated sliding resistance and the measured sliding resistance ranged from 0.653 to 2.44. Keywords: Adhesion, Friction, Normal stress, Sliding path length, Sliding resistance.

Fatigue failure is a phenomenon that often occurs in mechanical structures, especially in components that receive direct cyclic loading, e.g., marine facilities, automobiles, critical infrastructure, reservoirs, turbines, nuclear reactors, and features that work in extreme conditions. Several factors can affect fatigue resistance, including applied material type, environment temperature, microstructure state, residual stress, corrosion, and crack initiation. Accurately estimating fatigue life is critical. A variety of variables must be taken into the calculation to reduce the risk of dangerous failure. In this paper, a series of development and achievement reviews on the relevant phenomena and advanced research related to fatigue assessment is conducted. Consideration of fatigue assessment methodology, e.g., laboratory experiment and numerical calculation, is discussed to summarize relevant effects to characteristics of stress life, strain life, frequency-based, and fracture mechanic approaches. The review also presents the relationship of previous research and its relevance to the development of the recent study. The purpose of this paper is to provide state-of-the-art investigations as well as demonstrate the challenges of uncharted problems.

Geotechnical data used for reliability-based design (RBD) and load and resistance factor design (LRFD) calibration can be parsed into subgroups based on material type, location, test method, and so...

Nowadays, tungsten-based material is used for the core of projectile, while ceramic-based is used for the main material of armor. Tungsten-based material is chosen because it has density and hardness superior to steel based-material. Meanwhile, the ceramic-based can enhance mobility and resistance penetration of armor. Penetration of projectile on target generates an impact velocity parameter. This velocity has resulted when the projectile hits the target. Therefore, the value of impact velocity affects the quantity of depth of penetration (DoP) result. This paper reviews some papers regarding the penetration of tungsten-based projectile on ceramic-based armor. Furthermore, the content of these papers is reviewed by the narrative review method, and the impact velocity and DoP are the main data to analyze. Through this paper, impact velocity has a linear correlation with the DoP, the big of impact velocity produced bigger of DoP, and vice versa. Based on the data in this review, for the same impact velocity, material, and (almost) dimension of a projectile, SiC has better penetration resistance than B4C, TiB2, and Al2O3. Furthermore, the parameter of projectile dimension, projectile material type, target design, and material composition of the target also affects the DoP result.

The present research work is aimed to investigate the effect of infill pattern, density and material types of 3D printed cubes under quasi-static axial compressive loading. The proposed samples were fabricated though 3D printing technique with two different materials, such as 100% polylactic acid (PLA) and 70% vol PLA mixed 30% vol carbon fiber (PLA/CF). Four infill pattern structures such as triangle, rectilinear, line and honeycomb with 20%, 40%, 60%, and 80% infill density were prepared. Subsequently, the quasi-static compression tests were performed on the fabricated 3D printed cubes to examine the effect of infill pattern, infill density and material types on crushing failure behaviour and energy-absorbing characteristics. The results revealed that the honeycomb infill pattern of 3D printed PLA cubic structure showed the best energy-absorbing characteristics compared to the other three infill patterns. From the present research study, it is highlighted that the proposed 3D printed structures with different material type, infill pattern and density have great potential to replace the conventional lightweight structures, which could provide better energy-absorbing characteristics.

Highlights • Ultraviolet C at a dose of 1.5 J/cm2 to both sides is effective on some models of N95 s. • Straps may require additional disinfection to decontaminate properly. • SARS-CoV-2 decontamination does not apply to all hospital respiratory pathogens. • N95 model and fit-testing following irradiation need to be considered for UVC decontamination., Objectives There are currently no studies that have examined whether one dosage can be uniformly applied to different respirator types to effectively decontaminate SARS-CoV-2 on N95 filtering facepiece respirators (FFRs). Health care workers have been using this disinfection method during the pandemic. Our objective was to determine the effect of UVC on SARS-CoV-2 inoculated N95 respirators and whether this was respirator material/model type dependent. Methods Four different locations (facepiece and strap) on 5 different N95 FFR models (3 M 1860, 8210, 8511, 9211; Moldex 1511) were inoculated with a 10 μL drop of SARS-CoV-2 viral stock (8 × 107 TCID50/mL). The outside-facing and wearer-facing surfaces of the respirators were each irradiated with a dose of 1.5 J/cm2 UVC (254 nm). Viable SARS-CoV-2 was quantified by a median tissue culture infectious dose assay (TCID50). Results UVC delivered using a dose of 1.5 J/cm2, to each side, was an effective method of decontamination for the facepieces of 3 M 1860 and Moldex 1511, and for the straps of 3 M 8210 and the Moldex 1511. Conclusion This dose is an appropriate decontamination method to facilitate reuse of respirators for healthcare personnel when applied to certain models/materials. In addition, some straps may require additional disinfection to maximize the safety to frontline workers. Implementation of widespread UVC decontamination methods requires a careful consideration of model, material type, design, and fit-testing following irradiation.

Objective of the study. The objective of this study was to evaluate the effect of thickness change on the translucency of two recent monolithic zirconia dental ceramics used at different thicknesses. Materials and methods. A total of 60 disk-shaped specimens were prepared from two high-translucent tetragonal zirconia (Zolid ht+) and ultra-translucent cubic zirconia (Zolid fx), and divided equally into two groups according to material, each group with further subdivided into 3 subgroups according to thickness 0.5, 1, and 1.5 mm (n=10). A spectrophotometer was used to assess the CIE L*, a*, and b* for each thickness of the two zirconia ceramics. The Translucency Parameter (TP) was calculated. 1-way ANOVA and 2-way ANOVA statistical analysis of variance were performed (α=.05). Results. A statistically significant higher mean TP value was recorded with the ultra-translucent cubic zirconia group compared to that of high-translucent tetragonal zirconia regardless of thickness (P=0.008*< 0.05). Thickness had a significant effect on the translucency parameter of the two zirconia ceramics. Within group comparisons showed that for each of the two materials, the 0.5mm thickness recorded the statistically significant highest mean TP value, followed by the 1mm subgroup, whereas the statistically significant lowest mean TP value was recorded for the 1.5mm subgroup. Conclusions. Within the limitations of this study, it was found that material type and thickness had a significant effect on the translucency of high translucent monolithic zirconia.

Topography is a crucial characteristic reflecting the stability status of a landslide dam. The methods for measuring landslide dam topography in a laboratory-scale test study are currently operator dependent, time-consuming, or only applicable to the measurement of the two-dimensional section. In this paper, a laboratory-scale photogrammetric method based on the structure from motion (SfM) technique was proposed to measure the three-dimensional (3D) topography of a landslide dam. The SfM technique, which is a revolutionary, low-cost, user-friendly computer vision technique, was employed for reconstructing a landslide dam 3D computer model. A scientific method to determine the topography parameters of a landslide dam was put forward. Meanwhile, two materials with different particle sizes were used to simulate the formation process of the landslide dam in the laboratory-scale. Then, the measurement results of the two materials were compared. Five parameters of a landslide dam topography with 100 parallel measurement results for each parameter were obtained. The results show that the SfM technique could build a high-quality 3D point cloud in a laboratory scale. The proposed method of determining the topography parameters of a landslide dam was useful and has low measurement uncertainty. The material type affected the sparse density of the point cloud and then affected the measurement uncertainty of landslide dam topography parameters. The measurement uncertainty of the gravel-type landslide dam was significantly higher than that of the sand-type landslide dam. This research contributes to promoting the application of a photogrammetric method based on the SfM technique in geotechnical engineering laboratory-scale tests.

WOS: 000537819700007 Masonry walls are systems that are typically preferred in conventional structures. The complex structure of masonry walls makes it harder to determine wall behavior; however, wall behavior is affected by the types of material used in conventional walls and the way in which joints interact with masonry units. The aim of this study is to investigate the effect of joint thickness and material factors on wall performance. To accomplish this, materials used in historical and conventional structures are preferred. This study involved hollow bricks, clay bricks, NHL 3.5, and CEM 32.5. Three different joint thicknesses were used to set up 12 different combinations. Damage estimation of the wall was carried out by moving a live load under a constant vertical load. Different materials of different joint thicknesses and mechanical properties were studied for their effects on the wall. The results indicated that a joint thickness of 20 mm preferred in wall production was more convenient. The strength of walls produced from durable material was found to be higher. Yildiz Technical UniversityYildiz Technical University [2016-05-01-DOP05] This research was supported financially by Yildiz Technical University under contract 2016-05-01-DOP05.