Feed Rate Research Articles

Directed energy deposition processing of titanium alloys Ti-6242 and Beta 21S

ABSTRACT The objective of this research was to assess the response of two titanium alloys to directed energy deposition (DED). The alloys considered were Ti-6242 (near-alpha alloy) and Beta 21-s (beta alloy). The same experimental methods were employed for each alloy with different variable ranges. The first design of experiments (DOE) varied the laser power and traverse rate, with sample density as the dependent variable. A second DOE then varied laser power, traverse rate, hatch spacing, layer thickness and powder feed rate. The optimal parameter set determined was then utilised to prepare specimen for tensile testing and heat treatment studies. Both alloys were successfully processed, producing samples with densities >99.8% of full theoretical. The alloys also responded favourably to heat treatments, with resultant microstructures comparable to wrought. Mechanical properties were near wrought in terms of tensile strength but suffered from somewhat inferior tensile ductility.

Investigation of ultrasonic-assisted drilling temperature of SiCp/Al composites

ABSTRACT Due to their excellent properties and low manufacturing costs, SiC particle-reinforced Al matrix composites (SiCp/Al) find extensive application in automobile manufacturing and aerospace. However, SiCp/Al is less machinable. The ultrasonic-assisted drilling (UAD) decreases tool wear and enhances the quality of drilled holes when compared to conventional machining techniques. This paper investigates the effect of drilling temperature variations induced by processing conditions on the degree of softening of the base material during UAD of SiCp/Al. It also analyses the mechanism of how drilling temperature affects the quality of the holes made from the perspective of matrix softening. The study demonstrates a regularity in the impact of spindle speed, ultrasonic supply voltage(ultrasonic vibration amplitude), and feed rate as a function of drilling temperature. The effects of temperature changes caused by each of these factors on import/export edge defects, surface scratches on the hole wall, and tool machinability vary.

Microscopic investigation on micro electric discharge milling of AA6063-SiC composites

Metal matrix composites (MMC) have found applications in places where the utilization of conventional materials is limited. This also includes areas of micro- and meso-applications. However, micromachining of metal matrix composites by conventional methods poses difficulties due to the heterogeneous nature of the material and the presence of hard reinforcement particles. Micro-ED milling is a versatile micromachining process used to machine hard engineering materials. It employs a simple cylindrical cross-section tool, which is rotated and fed in predefined paths to generate intricate 3D features with good dimensional accuracy and surface finish. In order to study the machining performance of micro-ED milling process on metal matrix composites, micro-ED milling of AA6063-4 wt.% SiC composite fabricated by ultrasonic-assisted stir casting was carried out. The tool feed rate and tool rotation speed are important parameters as they aid in debris evacuation and influence material removal. So, the effect of tool feed rates, tool rotation speeds and discharge energies on the surface morphology and surface roughness of the machined channels were studied. The surface roughness parameters, namely Sa and Sq, were considered for the study. The least surface roughness, Sa and Sq, was observed at 2 µm/s for all the investigated discharge energies.

The effect of external flow on 3D orientation of a microscopic sessile suspension feeder, Vorticella convallaria.

Vorticella convallaria are microscopic sessile suspension feeders that live attached to substrates in aquatic environments. They feed using a self-generated current and help maintain the health of aquatic ecosystems and wastewater treatment facilities by consuming bacteria and detritus. Their environmental impact is mediated by their feeding rate. In ambient flow, feeding rates are highly dependent on an individual's orientation relative to the substrate and the flow. Here, we investigate how this orientation is impacted by flow speed. Furthermore, we examined whether individuals actively avoid orientations unfavorable for feeding. We exposed individuals to unidirectional laminar flow at shear rates of 0, 0.5, 1.0, and 1.5 s-1, and recorded their 3D orientation using a custom biplanar microscope. We determined that V. convallaria orientation became progressively tilted downstream as the shear rate increased, but individuals were still able to actively reorient. Additionally, at higher shear rates, individuals spent a larger fraction of their time in orientations with reduced feeding rates. Our shear rates correspond to freestream flows on the scale of mm s-1 to cm s-1 in natural environments.

Understanding the effects of cutting conditions on vibrations, surface integrity, machining temperature and tool wear mechanisms in end milling of AISI D2 Steel

The study explores vibrations, and thermal and tool wear (TW) mechanisms during dry end milling of AISI D2 steel employing two-, four-, and six- flute designs of TiAlN-PVD coated carbide end mill cutting tools. Because of multi-physics interactions in machining zone, supervised machine learning is used to understand TW, machining vibrations (MV), surface roughness (Ra) and the temperature of machining zone (TMZ), and to correlate the surface characteristics. A dedicated full factorial design of experiments campaign involving flutes (Fn), feed rate (Fr), and depth of cut (Doc) as variables is carried out to learn tool-workpiece interfacial characteristics. Results revealed that MV, Ra, TMZ and TW improved 57.82 %, 87.11 %, 79.22 % and 79.40 %, respectively at Fn = 6, Fr = 300 mm/min and Doc = 0.5 mm. Supervised machine learning (neural networks) and non-dominated sorting genetic algorithm (NSGA-II) based results showed reduction in vibrations by 89.84 %, Ra 97.39 %, tool-workpiece interaction temperature by 56.86 % and TW by 57.07 % by understanding mechanistic correlations of machining parameters with performance metrics.

MULTI-OBJECTIVE OPTIMIZATION OF ROTARY ASSISTED ELECTROCHEMICAL ARC DRILLING (R-ECAD) PROCESS USING GRA

Electrochemical Arc Drilling (ECAD) has demonstrated its effectiveness in micro-machining a variety of materials notwithstanding the inherent properties of materials. The increased machining properties of the ECAD method are a result of the inclusion of rotational effect of the working material. Better electrolyte replenishment, effective debris flushing, thin gas layer development, and spark uniformity are all credited with this improvement. Several input factors affect the machining characteristics of ECAD, making it difficult to simultaneously optimize these factors for several objectives. In order to maximise Material Removal Rate (MRR) and minimising Hole Overcut (HOC), this paper focuses on the multi-objective optimization of rotary-assisted ECAD (R-ECAD) input factors. Taguchi's L9 experimental design is used to produce micro-holes, and then Grey Relational Analysis (GRA) is used to perform the multi-objective optimization. The chosen input factors are working material rotation (WR), tool feed rate (FR) and applied voltage (V), whereas the chosen response factors are MRR and HOC. Results indicate that the rotating effect of the working material, which aids in the replenishment of electrolyte and the creation of a stable gas layer surrounding the tool, is notably the most significant input factor. For maximising the MRR and minimising HOC, the GRA-based optimised factors were found to be AIICIIBIII (60 rpm, 40 V, 0.8 mm/min). The responses are greatly improved by 39% as compared to the original machining, as demonstrated by microscopy images obtained during the GRA-based input factor optimization.

Childhood Opportunity and Acute Interstage Outcomes: A National Pediatric Cardiology Quality Improvement Collaborative Analysis.

The interstage period after discharge from stage 1 palliation carries high morbidity and mortality. The impact of social determinants of health on interstage outcomes is not well characterized. We assessed the relationship between childhood opportunity and acute interstage outcomes. Infants discharged home after stage 1 palliation in the National Pediatric Quality Improvement Collaborative Phase II registry (2016-2022) were retrospectively reviewed. Zip code-level Childhood Opportunity Index (COI), a composite metric of 29 indicators across education, health and environment, and socioeconomic domains, was used to classify patients into 5 COI levels. Acute interstage outcomes included death or transplant listing, unplanned readmission, intensive care unit admission, unplanned catheterization, and reoperation. The association between COI level and acute interstage outcomes was assessed using logistic regression with sequential adjustment for potential confounders. The analysis cohort included 1837 patients from 69 centers. Birth weight (P<0.001) and proximity to a surgical center at birth (P=0.02) increased with COI level. Stage 1 length of stay decreased (P=0.001), and exclusive oral feeding rate at discharge increased (P<0.001), with higher COI level. More than 98% of patients in all COI levels were enrolled in home monitoring. Death or transplant listing occurred in 101 (5%) patients with unplanned readmission in 987 (53%), intensive care unit admission in 448 (24%), catheterization in 345 (19%), and reoperation in 83 (5%). There was no difference in the incidence or time to occurrence of any acute interstage outcome among COI levels in unadjusted or adjusted analysis. There was no interaction between race and ethnicity and childhood opportunity in acute interstage outcomes. Zip code COI level is associated with differences in preoperative risk factors and stage 1 palliation hospitalization characteristics. Acute interstage outcomes, although common across the spectrum of childhood opportunity, are not associated with COI level in an era of highly prevalent home monitoring programs. The role of home monitoring in mitigating disparities during the interstage period merits further investigation.

Simulation and experimental study for enhancing surface integrity of micro-slots processed on Nimonic-263 super alloy via electrochemical machining

ABSTRACT The potential of micro electrochemical slotting is significant due to its adaptability and usefulness across diverse manufacturing applications. This technique holds potential, particularly for handling advanced engineering materials like superalloys, with a focus on applications requiring high strength, i.e., micro-cutting for gas-turbine parts, biomedical applications, etc. With this view, this article has been attempted to explore the influence of various considered machining factors, namely as; applied potential difference, tool feed rate (TFR), pulse supply, and modes of tool insulation on the performance measures, i.e. material removal rate (MRR) and surface roughness (Ra) while attempting micro-slotting in Nimonic-263 superalloy work samples. The entire experimentation was conducted on the in-house fabricated 3-axis micro-electrochemical setup designed for performing various complex machining operations at a miniature scale. Furthermore, this study has also been focused toward investigating the impact of varying the electrical conductivity by employing different tool materials (i.e. copper and SS304) on the process characteristics measured. The observed effects of the tool electrode’s conductivity have also been expressed and supported by performing the simulation for electric field distribution using COMSOL Multiphysics software. The experimental results have revealed that the process input variables remarkably influence MRR and Ra, mainly applied voltage and TFR. The best values of MRR and Ra attained with SS304 and copper tool electrodes were 1.521 mg/min and 0.721 mg/min, and 0.038 µm and 0.029 µm, correspondingly. The microstructure analysis has further been conducted on machined micro-slotted work samples that provided detailed insights into various surface integrity aspects, which are essential for microdevice applications.

The Effect of Rake Angle and Cutting Edge Radius on the Orthogonal Cutting Process of Ti6Al4V Alloy

This paper investigates the effect of rake angle, α, cutting edge radius, r, and feed rate, f, on the cutting force and cutting zone temperature during orthogonal dry cutting of Ti6Al4V. A numerical model representative of the 2D orthogonal cutting process is developed using ABAQUS/Explicit software. Johnson-Cook, (JC) constitutive material model is used to describe material plasticity. JC damage model and energy-based fracture criterion are used to describe damage initiation and evolution. Using Minitab-19 software, Taguchi L9 orthogonal array (3 × 3) is implemented to plan simulation trails. Assuming a constant cutting speed of 500 mm/min, three levels for each factor are considered α (-5°, 0°, 5°), &lt;em&gt;r&lt;/em&gt; (0.02, 0.04, 0.06 mm) and &lt;em&gt;f&lt;/em&gt; (0.1, 0.2, 0.3 mm). The cutting force and cutting zone temperature are analyzed using ANOVA. Based on a 90% Confidence Interval (90% CI), the results show that only feed rate significantly affects the cutting force. However, rake angle, cutting edge radius, and feed rate do not substantially affect cutting zone temperature.

Study and optimization of process parameters for deformation machining stretching mode

Monolithic thin-structure parts with intricate geometric designs are employed in a variety of aeronautical, medical, marine, and automotive applications, which include the moldlines of the fuselage, turbine blades, impellers, avionic shelves, irregular fins, prostheses, bone and joint support, and skull plates. The deformation machining process is the solution to this challenging and difficult-to-manufacture high-quality components with intricate narrow geometries at competitive prices. The aim of the present study is to assess the effect of process parameters of the deformation machining process wherein a thin, floor-like structure is created by milling and is then formed using a single-point incremental forming tool. Investigation involves the design and development of tooling required for the process followed by feasibility checking of the process. To examine the impact of different process parameters on the process response, the experiments were carried out using the design of experiments. The findings of this study indicate that different process parameters, including spindle speed, tool diameter, incremental step depth, and feed rate, have a substantial impact on the process response, like thickness, surface finish, and hardness. Uneven and non-uniform surface patterns during SEM indicate that it is needed to examine the impact of process parameters. This research involves the feasibility study of a new hybrid technique of deformation machining. Conventionally, a metallic structure is produced by joining various components through welding or by fastening. These methods require additional expenditure on equipment, storage, floor space, human resources, etc., with higher lead time. Joining increases weight and reduces fatigue strength. The creation of monolithic structures can eliminate all these disadvantages.

Finish turning of AISI 5140 tempered steel to improve machinability for engineering applications: An experimental approach with dry cutting

This study explores the best finish turning conditions for AISI 5140 tempered steel which is commonly used in automotive, agriculture and construction sectors thanks to its high strength and toughness properties. The steel is proper for surface hardening which makes it a perfect option to employ in various engineering applications. However, there are a few studies about this material and no paper is seen on finish turning operation which is highly critical to prepare the parts for workspace. Therefore, this work focuses on the impacts of feed rate, cutting speed and depth of cut parameters on roughness of workpiece along with cutting force and cutting temperatures while dry cutting of AISI 5140 steel. The results of the experiments evaluated with statistical analysis and Taguchi’s optimization approach. Accordingly, cutting speed is the dominant parameter on all response parameters namely surface roughness, cutting force and temperature with 92.6%, 61.6% and 91.6% contribution rate respectively. For maximum surface quality, highest cutting depth (0.3 mm) and cutting speed (200m/min) along with lowest feed rate (0.15 mm/rev) should be employed. Such an approach is expected to be a guide for the practical applications where tempered steels are used in different engineering disciplines.

Local thermal adaption mediates the sensitivity of Daphnia magna to nanoplastics under global warming scenarios

The toxicity of nanoplastics at environmentally relevant concentrations has received widespread attention in the context of global warming. Despite numerous studies on the impact of mean temperature (MT), the effects of daily temperature fluctuations (DTFs) on the ecotoxicity of nanoplastics remains largely unexplored. Moreover, the role of evolutionary adaptation in assessing long-term ecological risks is unclear. Here, we investigated the effects of polystyrene nanoplastics (5 μg L-1) on Daphnia magna under varying MT (20 °C and 24 °C) and DTFs (0 °C, 5 °C, and 10 °C). Capitalizing on a space-for-time substitution approach, we further assessed how local thermal adaptation affect the sensitivity of Daphnia to nanoplastics under global warming. Our results indicated that nanoplastics exposure in general reduced heartbeat rate, thoracic limb activity and feeding rate, and increased CytP450, ETS activity and Hgb concentrations. Higher MT and DTFs enhanced these effects. Notably, clones originating from their respective sites performed better under their native temperature conditions, indicating local thermal adaptation. Warm-adapted low-latitude D. magna showed stronger nanoplastics-induced increases in CytP450, ETS activity and Hgb concentrations under local MT 24 °C, while cold-adapted high-latitude D. magna showed stronger nanoplastics-induced decreases in heartbeat rate, thoracic limb activity and feeding rate under high MT than under low MT.

Experimental research and optimization based on response surface methodology on machining characteristics of cast Al-7Si-0.6 Mg alloy: Effects of cutting parameters and heat treatment

In this study, structural, mechanical and machining features of Al-7Si-0.6 Mg alloy manufactured by permanent mold casting (PMC) in both as-cast (AC) and T6 heat-treated (HT) conditions were investigated. Structural and mechanical properties were determined using conventional methods. Milling experiments were conducted with titanium aluminum nitride (TiAlN) coated carbide end mills in CNC milling machine under conditions of three different cutting speeds (V: 50, 80 and 110 m/min), feed rate (f: 0.08; 0.16 and 0.24 mm/rev) and constant depth of cut (DoC) (1.5 mm). It was seen that structure of AC Al-7Si-0.6 Mg comprised of aluminum-rich α-Al, coral-like eutectic Al-Si, primary Si, Mg2Si, Fe-rich plate, acicular β-Fe (β-Al5FeSi) and script-like π-Fe (π-AlSiMgFe) intermetallic phases. Eutectic Al-Si, primary Si, β-Fe and π-Fe phases in the structure of the alloy in the HT condition were partially dissolved and turned into an agglomerated and spherical state. While the hardness (HB), yield (YS) and tensile strength (TS) of the alloy raised with HT, the elongation to fracture (EF) reduced. While cutting force (CF), surface roughness (SR), built-up layer (BUL) and built-up edge (BUE) decreased with increasing V, they increased with increasing f in the milling of both cast and HT alloys. Adhered layers and feed marks were consisted of the cutted surfaces of the alloys. While the most adhered layer was observed in AC alloys at a low V (50 m/min) and high f (0.24 mm/rev) combination, the least adhered layer formation was observed at the highest V and the lowest f value in HT alloys. Optimum parameters with Response Surface Methodology (RSM) were determined as V: 125 m/min and f: 0.04 mm/rev in AC and HT cases. The statistical significance of V and f on CF and SR was revealed by analysis of variance (ANOVA), while mathematical models were improved to predict CF and SR.

Optimization of Electrospray Deposition Conditions of ZnO Thin Films for Ammonia Sensing.

This study focuses on the influence of electrospray deposition parameters on the morphology, topography, optical and sensing properties of ZnO films deposited on gold electrodes of quartz crystal resonators. The substrate temperature, precursor feed rate and emitter's voltage were varied. Zinc acetate dehydrate dissolved in a mixture of deionized water, ethanol and acetic acid was used as a precursor. The surface morphology and average roughness of the films were studied by scanning electron microscopy (SEM) and 3D optical profilometry, respectively, while the optical properties were investigated by diffuse reflectance and photoluminescence measurements. The sensing response toward ammonia was tested and verified by the quartz crystal microbalance (QCM) method. The studies demonstrated that electrospray deposition parameters strongly influence the surface morphology, roughness and gas sensing properties of the films. The deposition parameters were optimized in order for the highest sensitivity toward ammonia to be achieved. The successful implementation of the electrospray method as a simple, versatile and low-cost method for deposition of ammonia-sensitive and selective ZnO films used as a sensing medium in QCM sensors was demonstrated and discussed.

Effect of solid lubricant reinforcing on drilling performance of castamide and thermal analysis

AbstractThis study addresses the pressing need for enhancing the machining performance and hole quality of castamide by investigating the effects of solid lubricant addition and drilling parameters. Castamide, a highly crystalline polyamide synthesized via anionic ring‐opening polymerization, offers superior mechanical, physical, and chemical properties compared to conventional polyamide 6. However, its machining process, particularly drilling, remains a critical challenge due to its viscoelastic nature and sensitivity to heat generation. Using experimental investigations, thrust forces, drilling temperatures, hole geometry, and quality parameters are systematically analyzed and discussed. Notably, the study introduces Kestlub, a modified version of castamide with solid lubricant, and evaluates its drilling performance, a previously unexplored area in the literature. The research employs response surface methodology to model experimental data, considering both linear and quadratic effects of drilling parameters. Additionally, the significance of each parameter is assessed using ANOVA tables and Pareto charts, offering valuable insights into optimizing the drilling process for enhanced hole quality in castamide. It found that optimal drilling conditions occur at low rotational speeds and high feed rates, but thermal damage, influenced by factors like thermal conductivity and transition temperature, affects hole geometry and burr formation.Highlights Drilling performances of solid lubricant reinforced castamides were investigated. Drilling temperatures were recorded with a thermal camera and differential scanning calorimeter and thermal gravimetric analyses were performed. Drilling properties were analyzed statistically according to the response surface method. It found that optimal drilling conditions occur at low rotational speeds and high feed rates.

Neoadjuvant Nivolumab Plus Chemotherapy Followed By Response-Adaptive Therapy for HPV+ Oropharyngeal Cancer

Immune checkpoint inhibitors improve survival in recurrent and/or metastatic head and neck cancer, yet their role in curative human papillomavirus-positive oropharyngeal cancer (HPV+ OPC) remains undefined. Neoadjuvant nivolumab and chemotherapy followed by response-adaptive treatment in HPV+ OPC may increase efficacy while reducing toxicity. To determine the deep response rate and tolerability of the addition of neoadjuvant nivolumab to chemotherapy followed by response-adapted locoregional therapy (LRT) in patients with HPV+ OPC. This phase 2 nonrandomized clinical trial conducted at a single academic center enrolled 77 patients with locoregionally advanced HPV+ OPC from 2017 to 2020. Data analyses were performed from February 10, 2021, to January 9, 2023. Addition of nivolumab to neoadjuvant nab-paclitaxel and carboplatin (studied in the first OPTIMA trial) followed by response-adapted LRT in patients with HPV+ OPC stages III to IV. Primary outcome was deep response rate to neoadjuvant nivolumab plus chemotherapy, defined as the proportion of tumors with 50% or greater shrinkage per the Response Evaluation Criteria in Solid Tumors 1.1. Secondary outcomes were progression-free survival (PFS) and overall survival (OS). Swallowing function, quality of life, and tissue- and blood-based biomarkers, including programmed death-ligand 1 (PD-L1) expression and circulating tumor HPV-DNA (ctHPV-DNA), were also evaluated. The 73 eligible patients (median [range] age, 61 [37-82] years; 6 [8.2%] female; 67 [91.8%] male) started neoadjuvant nivolumab and chemotherapy. Deep responses were observed in 51 patients (70.8%; 95% CI, 0.59-0.81). Subsequent risk- and response-adaptive therapy was assigned as follows: group A, single-modality radiotherapy alone or transoral robotic surgery (28 patients); group B, intermediate-dose chemoradiotherapy of 45 to 50 Gray (34 patients); and group C, regular-dose chemoradiotherapy of 70 to 75 Gray (10 patients). Two-year PFS and OS were 90.0% (95% CI, 0.80-0.95) and 91.4% (95% CI, 0.82-0.96), respectively. By response-adapted group, 2-year PFS and OS for group A were 96.4% and 96.4%, and group B, 88.0% and 91.0%, respectively. Lower enteral feeding rates and changes in weight, as well as improved swallowing, were observed among patients who received response-adapted LRT. Pathologic complete response rate among patients who underwent transoral robotic surgery was 67.0%. PD-L1 expression was nonsignificantly higher for deeper responses and improved PFS, and ctHPV-DNA clearance was significantly associated with improved PFS. This phase 2 nonrandomized clinical trial found that neoadjuvant nivolumab and chemotherapy followed by response-adapted LRT is feasible and has favorable tolerability, excellent OS, and improved functional outcomes in HPV+ OPC, including among patients with high-risk disease. Moreover, addition of nivolumab may benefit high PD-L1 expressors, and sensitive dynamic biomarkers (eg, ctHPV-DNA) are useful for patient selection. ClinicalTrials.gov Identifier: NCT03107182.

Experimental study on the ultrasonic assisted face turning residual stress

ABSTRACT The Experimental study investigates the impact of ultrasonic-assisted face turning (UAFT) on cutting forces, tensile residual stress, and surface topography. The primary objective is to identify optimal cutting parameters that yield a smoother surface finish while concurrently reducing cutting forces and tensile residual stress. The tests were conducted on a lathe machine equipped with ultrasonic assistance, using 1.7225 steel as the workpiece material. Various cutting parameters, including feed rate, spindle speed, and turning state, were varied. The results illuminate the significant efficacy of ultrasonic assisted face turn (UAFT) in improving surface topography, compared to conventional turning (CT). The optimal turning parameters for achieving the smoothest surface finish were determined to be a higher spindle speed and lower feed rate. Moreover, the introduction of ultrasonic vibration led to a substantial reduction in cutting forces, primarily attributable to the diminished attrition between the cutting tool insert and the work part. Overall, the experimental study demonstrates the effectiveness of ultrasonic-assisted face turning in enhancing surface topography, with an improvement of approximately 39%. Additionally, the study demonstrated a reduction in cutting forces by approximately 50% and a decrease in tensile residual stress by approximately 33.8%. These findings underscore the potential of ultrasonic vibration as a tool for optimizing cutting parameters to achieve desired surface finishes in machining applications.

Deep Rolling Techniques: A Comprehensive Review of Process Parameters and Impacts on the Material Properties of Commercial Steels

The proposed review demonstrates the effect of the surface modification process, specifically, deep rolling, on the material surface/near-surface properties of commercial steels. The present research examines the various process parameters involved in deep rolling and their effects on the material properties of AISI 1040 steel. Key parameters such as the rolling force, feed rate, number of passes, and roller geometry are analyzed in detail, considering their influence on residual stress distribution, surface hardness, and microstructural alterations. Additionally, the impact of deep rolling on the fatigue life, wear resistance, and corrosion behavior of AISI 1040 steel is discussed. Engineering components manufactured by AISI 1040 steel can perform better and last longer when deep rolling treatments are optimized with an understanding of how process variables and material responses interact. This review provides critical insights for researchers and practitioners interested in harnessing deep rolling techniques to enhance the mechanical strength and durability of steel components across diverse industrial settings. In summary, the valuable insights provided by this review pave the way for continued advancements in deep rolling techniques, ultimately contributing to the development of more durable, reliable, and high-performance steel components in diverse industrial applications. The establishment of generalized standardizations for the deep rolling process proves unfeasible because of the multitude of controlling parameters and their intricate interactions. Thus, specific optimization studies tailored to the material of interest are imperative for process standardization. The published literature on the characterization of surface and subsurface properties of deep-rolled AISI 1040 steel, as well as process parameter optimization, remains limited. Additionally, numerical, analytical, and statistical studies and the role of ANN are limited compared with experimental work on the deep rolling process.

Fundamental comminution efficiency gains with the CAHM platform technology

ABSTRACT The Conjugate Anvil Hammer Mill (CAHM) is a platform technology invented by Lawrence Nordell that embodies Dr Klaus Schönert’s guiding principles for highly efficient comminution into a series of commercial, production-scalable devices across multiple product size ranges. Schönert demonstrated that unconfined, compression breakage of single particles (or thin particle beds) between parallel plates produces the most energy efficient particle breakage. The CAHM Mark 1 Prototype and the MonoRoll are 2 new comminution devices that leverage these fundamental principles to produce comparable breakage at a fraction of the energy consumed by SAG mills, Ball mills or even High Pressure Grinding Rolls. The CAHM machine prototype has been tested at feed rates in excess of 60 t/h and is robust enough to be operated at a mine site for a pre-commercial demonstration. The MonoRoll is a 2 t/h retrofit of an existing pilot-scale ball mill. A mining industry consortium led by the Canada Mining Innovation Council and supported by Quebec and Federal government funding has designed, fabricated and tested both prototype machines over the last 4 years. Beyond the dramatic energy savings, implementing these technologies will generate additional benefits from simpler circuits and reduced scope 1, 2 and 3 carbon emissions. This paper reviews the design of these 2 prototypes in the context of Schönert’s fundamental principles for efficient breakage.

Effect of parasite infection and invasion history on feeding, growth, and energy allocation of cane toads

Abstract The energy allocation decisions that organisms make can differ between sexes and populations and can be influenced by factors such as age and parasite infection. We conducted experimental parasite infections on common-garden reared cane toads originating from sites across the species’ invasive range in Australia to assess how sex, parasite infection, and invasion history affected the toad’s food intake, growth rate, and organ weights. Female toads had larger fat stores, larger livers, and larger gonads than did males, reflecting increased investment into gametes. Growth rate did not differ between the sexes. Lungworm infection increased feeding by male but not female toads and increased fat storage in all toads. Fat body, liver, gonad sizes, and feeding rates all differed among toads from different locations within the toad’s invasion transect across Australia, even though our measurements were made under standardized conditions on captive animals. Toads from populations close to the invasion front ate more, had heavier fat bodies, and had larger livers than did toads from long-colonized areas, but they had smaller gonads. This pattern reflects the evolution of a more dispersive phenotype among invasive populations, whereby the rate of dispersal is enhanced by increased energy intake and storage, and delayed reproduction.