Head Configuration Research Articles

Contemporary issues of the birth trauma

Background. Birth trauma is a group of diseases caused by mechanical factors during childbirth. Birth trauma is an interdisciplinary problem, affecting various fields of medicine, such as obstetrics, pediatrics, child neurology and other sciences. Birth trauma occupies an important place in the structure of perinatal morbidity and mortality. Birth injuries of newborns during vaginal birth occur in 3.6% of cases, during cesarean section — in 1.2%. However, at present, despite a comprehensive study of the problem, the incidence of birth trauma in newborns remains high. Along with obstetric birth trauma, spontaneous birth trauma also occurs — not associated with any obstetric care.Purpose of review. To summarize and analyze the available data on the causes of birth trauma in newborns depending on the type of birth injury.Materials and methods. The review includes published data over the past 10 years regarding the study of the causes of the main types of birth injuries in newborns. The literature search was conducted in Web of Science, Google Scholar, PubMed, and ELibrary databases.Results. The problem of fetal-pelvic disproportion in the genesis of the development of risk factors for maternal-fetal trauma remains relevant. Fetal macrosomia is one of the most significant factors in birth trauma. The most common skull injury in newborns is cephalohematoma. According to the mechanism of occurrence, birth trauma is divided into spontaneous — occurring during physiological childbirth — and obstetric — associated with any obstetric benefits. The degree of configuration of the fetal head plays a significant role in the pathogenesis of birth trauma. Birth trauma is considered as a systemic reaction on the part of the newborn’s body, which leads to a breakdown of compensatory and adaptive mechanisms and the development of critical damage to the central nervous system and is differentiated from birth damage, which includes only local changes.Conclusion. To search for preventive measures aimed at preventing birth injuries in newborns, it is necessary to systematize the groups of causes that influence the increased risk of birth injury. Timely assessment of the pathological configuration of the fetal head is extremely important when deciding on the advisability of using obstetric aids during vaginal operative delivery, since it is an early predictor of the formation of fetal-pelvic disproportion — a significant factor in birth trauma in the newborn. In recent years, taking into account the active study of molecular genetic mechanisms in the genesis of the formation of various pathological conditions, the search for various genetic and epigenetic factors that influence the risk of developing birth traumatic injuries in a newborn against the background of individual susceptibility to the effects of any physical factors during childbirth.

End Connectors Stress Analysis for Horizontal Pressure Vessel

The gas and oil industry extensively utilizes horizontal pressure vessels to store its primary sources. These vessels are designed to withstand high levels of pressure and to release contents in a controlled manner. Although the sphere-shaped storage container is widely regarded as a better-engineered structure, the ease of manufacturing makes horizontal pressure vessels the preferred choice. This paper presents an in-depth analysis of stress distribution in horizontal pressure vessels with various end connections, including hemispherical, ellipsoidal, flat head, and tori-spherical configurations. The study involves analytical and finite element analysis (FEA) to compare the stress distribution across these above-mentioned end connections. Key vessel dimensions, such as internal diameter, vessel thickness, and end connections, have been determined through analytical design. A detailed structural analysis aided in determining which among the different end connectors is best suitable for industry usage.

Investigation on uneven flow distribution in triply periodic minimal surface heat exchangers

The development in manufacturing engineering has made it possible to adopt the unique porous structure known as the triply periodic minimal surface to increase energy efficiency in a variety of energy-related sectors. With the unique morphological characteristics, triply periodic minimal surface exhibits remarkable mechanical strength and thermal performance, which makes it a potential candidate for compact, high-performance heat exchanger constructions. In this study, a theoretical model based on triply periodic minimal surface porous media is developed. Based on the hypothesis that the triply periodic minimal surface is isotropic and the heat transfer intensity of fluid and solid is uniform throughout the core of the heat exchanger, the simulation of the full-size heat exchanger is simplified by using a porous media model. The flow distribution characteristics of triply periodic minimal surface heat exchangers, as well as the effect mechanism of key factors, including the channel porosity, header configuration, the type of triply periodic minimal surface, the core length and Reynolds number on the flow distribution performance, are investigated. A dual-header configuration is proposed to improve the flow uniformity of triply periodic minimal surface heat exchangers. The results indicate that the flow distribution performance of triply periodic minimal surface based heat exchangers can be enhanced by the reduction of channel porosity. When the cold-side porosity is 0.7, the flow rate deviates from the mean value by 220% at its maximum for a Primitive heat exchanger. A dual-header configuration eliminates the columnar extreme high velocity space in the core and greatly reduces the “weak zone” of flow distribution, which improves the flow non-uniformity by 45–90% over the single-inlet headers. This paper provides data and theoretical support for the optimal design and practical application of the complex, high-performance triply periodic minimal surface based heat exchangers.

Investigating the Impact of Circular Sector Pole Head Structure on the Performance of a Multipole Magnetorheological Brake

The magnetorheological brake (MRB) epitomized a revolutionary modification in the braking systems because of its extremely efficient and well-controlled performance. To increase the safety and controllability of automotive braking system, researchers have developed a different MRB structures. Although much research on magnetorheological brakes has shown positive results in terms of brake torque, braking time, thermal efficiency, etc., the ability to increase braking force by expanding the disc surface, through which the magnetic field operates in a compact structure, is restricted. To address this issue, a new multipole MRB configuration with a unique pole head design that maintains compactness. Initially, the conceptual design was achieved by leveraging the combined impact of the twin disc-type structure and multipole concept. The model was used in a dynamic simulation to show how the braking torque of a magnetorheological braking system varies with coil current. The effects of circular sector pole head shape on braking performance were investigated using COMSOL Multiphysics software (version 5.5). A three-dimensional electromagnetic model of the proposed MRB was developed to examine the magnetic flux intensity and the impact of magnetic field dispersion on the proposed pole head structure of a magnetorheological brake. Based on simulation results, the circular sector pole head configuration is capable of increasing the active chaining regions for the MR fluid on the rotor surface, allowing for a more effective use of magnetic flux throughout the whole surface of a rotating brake disc, thereby increasing the magnetic field usage rate. The acquired simulation results show an increase in braking torque while keeping a compact and practical design structure.

DESIGN AND ANALYSIS OF PRESSURE VESSEL USING DIFFERENT MATERIALS

This project explores the field of Finite Element Analysis (FEA) in relation to pressure vessels that have different head configurations, while ensuring that the cylindrical volume and thickness remain uniform. The project adheres to ASME standards, specifically Section VIII, Division I, and focuses on designing a pressure vessel that can withstand a pressure of 8 bar within a volume of 24 liters. The main objective of using FEA is to identify areas of stress concentration in each head design. In industrial settings, pressure vessels play a crucial role in containing fluids or gases under varying pressures. The choice of head configuration significantly impacts the distribution of stress and the overall structural strength. This project specifically utilizes ANSYS software for static and thermal analyses to compare stress distribution in pressure vessels with flat heads, elliptical heads, and other common head designs. The goal is to identify configurations that exhibit lower stress levels, with a particular emphasis on practical scenarios that favor elliptical heads. Additionally, the project explores finite element modeling techniques to evaluate pressure vessels made from different materials such as Nimonic 80A and SA516 Gr70 under high-stress conditions

Matching strategy and skip-scale head configuration guideline based traffic object detection

The configuration of the detection head has a significant impact on detection performance. However, when the input resolution or detection scene changes, there is not a clear method for quantitatively and efficiently configuring the detection head. We find that there is a rule of matching degrees between the object scale and the detection head across different input resolutions or detection scenes by careful analysis. Based on this matching rule, we propose simple yet very effective methods for detection head configuration. The methods consist of two main parts. The first is the matching strategy of detection head and object scale, which can handily and quantitatively guide the rational configuration of detection heads to effectively detect objects at vastly different scales. The second is the skip-scale detection head configuration guideline, which instructs to replace multiple detection heads with only two detection heads to decrease model parameters as well as achieve high detection accuracy and speed. Extensive experimental results on three benchmarks, BDD100K, nuImages and our proposed ETFOD-v2, validate the effectiveness and convenience of our proposed methods, showing potential application prospect in future intelligent traffic systems. The code and ETFOD-v2 dataset are available in https://github.com/YiShi701/MR-Net.

Mole‐Inspired Robot Burrowing with Forelimbs for Planetary Soil Exploration

The biological world serves as a vast reservoir of inspiration for human innovation, particularly in the realm of robotics designed to navigate intricate granular environments. Among these creatures adept at burrowing, the mole stands out due to its exceptional body structure and unparalleled efficiency, surpassing most engineering burrowing systems. Consequently, the mole serves as an ideal model for designing highly efficient burrowing robots. This study introduces a mole‐inspired robot burrowing with forelimbs, specifically designed for planetary soil exploration. By closely examining the distinctive body morphology of moles, a forelimb burrowing mechanism is devised through biomimetic mapping, and its kinematics is thoroughly analyzed. A robot prototype is developed and an experimental setup is constructed to evaluate its burrowing performance. A series of tests are conducted to assess the capabilities of the robot, including forelimb burrowing, robot crawling, and robot burrowing. The results demonstrate that the proposed mole‐inspired burrowing robot is capable of crawling and burrowing to a certain depth using its forelimbs. Although it exhibits some upward displacement, this issue can be mitigated by modifying the head configuration and adjusting the forelimb posture to effectively overcome the vertical stress and lift force exerted by granular soils due to intensity gradient.

Heterogeneities of the perceptual-motor style during locomotion at height.

In a recent review, we summarized the characteristics of perceptual-motor style in humans. Style can vary from individual to individual, task to task and pathology to pathology, as sensorimotor transformations demonstrate considerable adaptability and plasticity. Although the behavioral evidence for individual styles is substantial, much remains to be done to understand the neural and mechanical substrates of inter-individual differences in sensorimotor performance. In this study, we aimed to investigate the modulation of perceptual-motor style during locomotion at height in 16 persons with no history of fear of heights or acrophobia. We used an inexpensive virtual reality (VR) video game. In this VR game, Richie's Plank, the person progresses on a narrow plank placed between two buildings at the height of the 30th floor. Our first finding was that the static markers (head, trunk and limb configurations relative to the gravitational vertical) and some dynamic markers (jerk, root mean square, sample entropy and two-thirds power law at head, trunk and limb level) we had previously identified to define perceptual motor style during locomotion could account for fear modulation during VR play. Our second surprising result was the heterogeneity of this modulation in the 16 young, healthy individuals exposed to moving at a height. Finally, 56% of participants showed a persistent change in at least one variable of their skeletal configuration and 61% in one variable of their dynamic control during ground locomotion after exposure to height.

Impact of toothbrush head configuration and dentifrice abrasivity on non-carious cervical lesions in-vitro

ObjectiveTo investigate the effect of toothbrush head configuration and dentifrice slurry abrasivity on the development of simulated non-carious cervical lesions (NCCLs) in vitro. MethodsExtracted premolars were randomly allocated into 15 groups (n = 16) generated by the association between toothbrush head configuration (flat-trimmed, rippled, cross-angled/multilevel/rubbers added, cross-angled/multilevel/flex head, feathered) and dentifrice slurry abrasivity (low/medium/high). Teeth were mounted on acrylic blocks and had their roots partially covered with acrylic resin, leaving 2-mm root surfaces exposed. Toothbrushing was performed for 35,000 and 65,000 double-strokes. Specimens were analyzed using non-contact profilometry for dental volume loss (mm3) and lesion morphology. Data was analyzed using ANOVA with pairwise comparisons and Kruskal-Wallis tests. ResultsThe two-way interaction between toothbrush head configuration and slurry abrasivity was significant (p = 0.02). At 35,000 strokes, the flat-trimmed and cross-angled/multilevel/rubbers added toothbrushes caused the highest loss, when associated to the high-abrasive slurry (p<0.05); whereas cross-angled/multilevel/flex head showed the least loss, when associated to the low-abrasive (p<0.05). At 65,000, more dental loss was observed for all toothbrushes when associated to the high-abrasive slurry, with flat-trimmed causing the highest loss (p < 0.05). Lower dental loss rates were observed for cross-angled/multilevel/flex head associated to the low-abrasive slurry when compared to the other toothbrushes (p < 0.05), except to feathered (p = 0.14) and rippled (p = 0.08). Flat lesions (mean internal angle ± standard-deviation: 146.2°± 16.8) were mainly associated with low-abrasive slurry, while wedge-shaped lesions (85.8°± 18.8) were more frequent with medium- and high-abrasive slurries. ConclusionThe development, progression and morphology of simulated NCCLs were modulated by both toothbrush head configuration and dentifrice abrasivity. Clinical significanceDental professionals should consider both the type of toothbrush and dentifrice abrasivity in the management plan of patients at risk of developing NCCLs.

Transforming Text Generation in NLP: Deep Learning with GPT Models and 2023 Twitter Corpus Using Transformer Architecture

This paper presents the design, implementation, and evaluation of a Transformer-based Generative Pre-trained Transformer (GPT) model tailored for character-level text generation. Leveraging the robust architecture of the Transformer, the model has been trained on a corpus sourced from social media text data, with the aim of exploring the intricacies of language patterns within a condensed and informal text setting. Key aspects of the model include a multi-head self-attention mechanism with a custom head configuration, positional embeddings, and layer normalization to promote stability in learning. It operates with a defined set of hyperparameters: a batch size of 32, a block size of 128, 200 iterations, a learning rate of 3e-4, and employs 4 attention heads across 4 layers with an embedding dimension of 384. The model has been optimized using the AdamW optimizer and includes regularization through dropout to prevent overfitting.Through a series of training iterations, the model demonstrates a converging behavior in loss metrics, indicating effective learning, and showcases the capacity to generate coherent text sequences post-training. Training and validation losses have been reported, revealing the nuances in model performance and generalization capabilities. The generated text samples postulate the model's potential in capturing the contextual flow of the dataset. This study further plots the loss curves, visually representing the training dynamics and convergence patterns. The final model, encapsulated within a PyTorch framework, presents a step forward in the realm of neural text generation, contributing to the ongoing advancements in language modeling and its applications in understanding and generating human-like text.

Development of a Framework for Cost–Benefit Analysis of I-Head and T-Head Groynes Based on Scour and Turbulent Flow Characteristics

River bank protection is a vital component of sustainable development. This study investigates and compares the scour and flow features around two different types of groynes, an unsubmerged I-head groyne (IHG) and T-head groyne (THG), to provide insights into their performance and efficiency in river reaches. Experiments were conducted to examine the scouring pattern, mean and turbulent flow characteristics including 3D mean flow velocity distribution, Reynolds stresses, turbulent kinetic energy, and bed shear stress near the bed region around the groynes under similar flow conditions. The results indicated that THG had a maximum equilibrium scour depth over three-fold greater than IHG. For both the IHG and THG cases, it was observed that there is a direct correlation between the location of maximum negative vertical velocity and its magnitude to the region of maximum local scour and its depth. All the stresses of high magnitude are found along the propagation of the detached shear layer profile, which turns back sharply downstream towards the bank containing the IHG while remaining mostly away from the bank in the case of THG. The effective bank protection length was estimated to be two-fold the groyne length in the case of IHG and three-fold the groyne transverse length in the case of THG. Cost–benefit analysis of the two groyne types shows IHG as the more cost-efficient groyne with respect to bank protection lengths. This study provides valuable insights for developing design methodologies aimed at promoting the wider utilization of different head-shape groynes in river reaches and aids in selecting appropriate groyne head configurations that align with specific field requirements.

Numerical Study of Different Steady-State Flow Rigs for the Tumble Motion Characterization of a Four-Valve Cylinder Head

It is widely accepted that in-cylinder airflow structure strongly affects the performance and combustion of internal combustion (IC) engines. In order to enhance turbulence levels at the time of combustion, modern spark ignition engines (SI) usually employ a tumbling motion inside the cylinder. The tumble generated during the intake phase is mainly controlled by the cylinder head, inlet valves and ports configuration. The use of steady-state flow rigs is a common method to characterize the tumble generating ability of a given configuration. The purpose of this study is to perform CFD numerical simulations of two widely used tumbling measuring steady-state flow rig configurations, in order to compare and correlate the tumble ratios obtained from each one of them. A typical modern four-valve shallow pentroof cylinder head is considered and the flow is simulated for various inlet valve lifts. The results highlight the mass flow rate and tumble ratio differences between the two configurations.

Tensile behaviors and configurations of double-headed bar overlap connections for precast concrete members

The superiorities in construction time, cost, and quality of precast RC structures are accompanied by the challenges in connection, particularly in steel bars connections between RC components. The extensively used steel bar connections for either grouted sleeve splice connection or grouted spiral-confined lap connection requires on-site grouting, which is a concealed construction process with increased the risk of grouting defects, thereby impairing connection reliability. The confined headed bar connection (CHBC) with visible on-site construction has been proposed to address the unseen grouting defects concerns. However, modern structures that use large-diameter or high-strength rebars present higher demands for steel bar connection capacity. For CHBC, it is suggested to use either a long connection length or a large-size head to satisfy the capacity demand. However, the long connection length can increase field wet operation, which is disadvantage in precast concrete construction. The large-size head can help reduce the connection length, but it can cause inconvenience including construction congestion and the increased eccentric bending moment under tension. This paper presents the CHBC with double-head configuration, which can reduce the single head size. The proposed CHBC consists of confinement stirrups and two overlapped headed bars and the stirrup confining the core concrete can also improve the CHBC capacity. Experimental investigation on 21 CHBC specimens has been carried out. The failure modes, bearing capacity, and stirrup strain development have been studied. Effects of the double-head configuration and confinement stirrup ratio have been analyzed through experimental and numerical investigation. Results show that the double-head configuration has a minor impact on the tensile capacity of CHBC while the increase of confined stirrup ratio can improve the tensile capacity of CHBC. Configuration details of size and spacing for stirrup reinforcement in CHBC are proposed. Based on the test results, CHBC tensile capacity prediction method is suggested, which can take the head configuration into account.

Microscopic study of normal deformed bands in 167,169,171Lu

The normal deformed bands of [Formula: see text]Lu isotopes have been studied by using projected shell model approach. The band head spins, configurations and energies of all the normal deformed bands are reproduced well by the above said approach. The present calculations have predicted [Formula: see text] band head spin for [523]7/2− bands of [Formula: see text]Lu. The observed systematics of aligned angular momenta and the experimental differences in frequencies around the backbends for all the normal deformed bands are reproduced well by the theoretical results. Besides this, the observed backbends or upbends in these isotopes may be ascribed to the alignment of a pair of neutrons in the neutron [Formula: see text] orbital. Although the theoretical [Formula: see text] values obtained from the projected shell model wavefunctions overestimate the experimental [Formula: see text] values in [Formula: see text]Lu, yet they are close to the measured values, considering the precision of measurement. The reduction in the theoretical [Formula: see text] values around the band crossing region may be ascribed to change in nuclear structure of yrast bands due to neutron pair alignment in [Formula: see text] orbital.

Effect of Pole Head Profile on Torque Performance of a Disc-Type Multipole Magnetorheological Brake

A magnetorheological brake (MRB) works on the shearing effect of MR fluid in the magnetic field to develop resistance between the stator and the rotor, which are relative moving surfaces. Researchers achieved high torque volume ratios in magnetorheological fluid braking systems by adding multiple layers and using multipole approaches. Even though several designs already exist, there is a need for innovative ideas and advanced structures of MRBs for practical engineering applications. The number of magnetic poles, pole geometry and placement have a significant effect on the performance of multipole MR brakes. This research focused on the effect of the pole head geometry in a multipole dual disc compact MR brake to understand the relationship between the geometry and its magnetic flux flow. The magnetic field generated by the electromagnetic coil’s orthogonal travel through pole heads, rotor and MR fluid layers results in friction to fulfill the action of braking that achieves maximum brake torque. This flow depends on the magnetic pole head area and corresponding core dimensions. This study considered polygon, square, hexagon, trapezoid and ellipse pole head profiles in place of the conventional circular pole and the best possible core dimensions were used for each geometry. To study the brake’s performance, COMSOL Multiphysics software (version 5.5) commonly used for 3D electromagnetic modeling was used to simulate and examine the magnetic flux intensity for various pole head configurations. Results indicate an improvement compared to previous works, considering the same dimensional limitations and the flux leakage between the adjacent poles being much less. The hexagonal and elliptical pole heads had better magnetic field area, magnetic intensity distribution and higher magnetic flux lines piercing through the MR fluid perpendicularly than the circular and square pole heads. An increment of 3.88% for braking torque performance was obtained, and the braking torque was significantly enhanced.

Evaluation of Dynamic Flashing Yellow Arrow Decision Support System in the Field Using Before and After Real-Time Data

A permissive left turn is one of the most dangerous movements a driver can make because the driver travels across opposing traffic lanes. In recent years, flashing yellow arrow (FYA) signals have been proven to help drivers make safer left turns. The four-section signal display with FYA permissive left-turn indication creates an opportunity to enhance the left-turn phase with a variable mode that can change on demand. A challenge to using this system is knowing the best times of day to apply the FYA indication. The authors developed an exclusive hardware platform: first, to provide a generic device compatible with the different controller types used by different jurisdictions and, second, to automate selection of the FYA left-turn modes based on available gaps in the opposing traffic at intersections acquired in real time from existing sensors in the field. Phase IV provided conclusive field testing and evaluation of the decision support system (DSS), by switching between red and FYA modes in a rational manner consistent with driver expectations and left-turning gap acceptance thresholds. It was also concluded that coordinated signals with long cycle lengths, 3 min and longer, help provide adequate gaps even in heavy traffic patterns since most of the vehicle arrivals are in platoons and at the beginning of the cycle. The analysis showed that the utilization factor for the DSS recommendations for all the intersections ranged between 65% and 75% during peak conditions on weekdays and between 90% and 95% during off-peak conditions and weekends. The total delay in the before study for all the intersections amounted to 737 vehicle-hours and in the after-study was 440 vehicle-hours of delay. An overall reduction of about 40% in delay which confirms the operational benefit of the dynamic FYA DSS. The developed platform is applicable at any four-section head configuration to maximize safety and efficiency of the intersections.

Numerical Simulation Study on Injection and Mixing Characteristics of Supercritical RP-3 Aviation Kerosene

A real gas calculation model is developed using the P-R equation of state to investigate the injection and mixing characteristics of supercritical RP-3 aviation kerosene in the combustion chamber. In this investigation, n-decane is used as an alternative fuel, and the physical parameters of n-decane at the supercritical state are calculated. The jet and mixing characteristics of supercritical kerosene in different combustion chamber models are investigated by this calculation model. The combustion chamber head configuration suitable for supercritical kerosene is obtained by analyzing the spatial inhomogeneity, the deviation of equivalent ratio fluctuation, and the mixing degree.

Responses of Structural Components of a Full-Scale Nailed Retaining Structure under the Influence of Surcharge Loading and Nail Head Configuration: A Numerical Study

Soil-nailing is a simple and economical method of stabilizing cut slopes and retaining excavation. Most of the soil-nailing related studies, in particular the experimental work, were conducted in idealized or homogeneous ground, but such a result might not necessarily be representative. Thus, for a more representative study, instead of treating the ground as homogeneous it should be treated as a system of horizontal layers. This study assessed the performance of a full-scale nailed retaining structure for a foundation pit of a 20-storey building through a series of numerical analyses. The influence of full-face facing thickness, nail head geometrical configuration (size and thickness) and surcharge loading on the response of the structural components of the soil-nailing system adopted is the main concern. The results were evaluated in terms of axial force, shear force and bending moment of the structural facing element and the horizontal displacement of the soil retained behind the facing element. In both cases, the distribution of nail axial (tensile) force in each nail reinforcement was also compared and evaluated. It was found that the thickness of full-face facing affected the facing shear force and bending moment, while the surcharge loading influenced the facing axial force and the horizontal displacement of the retained soil and that the magnitude of the axial force registered at the fixed end was governed by the size of the discrete nail head.

Design Procedure of a Mono-Anchor Head for 2360 MPa High-Strength Steel Strand

In this paper, a design procedure for a mono-anchor head anchoring a 2360 MPa high-strength steel strand is proposed. The performance criteria of the existing anchor head based on PTI (Post-Tensioning Institute) have been reorganized so that they can be evaluated based on the plastic hoop strain appearing at the top of the wedge hole. In order to design a mono-anchor head that does not exceed the permissible performance standard, the stress and deformation mechanisms of the mono-anchor head were investigated. It was confirmed that the external force was locally concentrated at the top of the wedge hole due to the interaction between the components of the anchorage device. An investigation based on the finite element method was conducted to identify the degree of external force concentration at the location and establish the relationship with the plastic hoop strain. An analytical investigation was conducted according to the design variables of the mono-anchor head, and in this process, static load tests and material tests were conducted to create an analytical model that reflects the actual behavior of the anchorage system. An equation was established regressionally so that the plastic hoop strain, which is a performance criterion, can be calculated according to the configuration and yield strength of the anchor head. Following the proposed design procedure, the configuration can be properly determined when the yield strength determination is limited due to material supply and demand. In addition, when space is limited during the construction of an anchorage device, the dimensions of an anchorage device in a small size can be determined, and the yield strength appropriate for that size can be determined.

Co-Harvest and Anaerobic Co-Storage of Corn Grain and Stover as Biomass Feedstocks

Highlights Cutting height and harvest date were used to alter stover moisture content, yield, and composition. Anaerobic co-storage of grain and stover limited losses to less than 6% of dry matter. Extent of fermentation was greater for higher moisture stover than grain, but total acids were less than 5 g kg-1. Reducing the harvester cutter head rotational speed resulted in a greater fraction of whole corn kernels. Abstract. This research investigated the utility of co-harvesting and anaerobic co-storage of corn grain and stover to positively influence their physical and chemical characteristics as a biomass feedstock. Corn grain and stover were harvested in 2019 and 2020 with a self-propelled forage harvester. Stover yield, moisture content, and composition were altered by the harvest date, stubble height, and header configuration. Harvest date had the utility of varying the stover moisture content (p &amp;lt; 0.001) from 42.3% to 53.5% (w.b.) and 43.1% to 53.9% (w.b.) for the 2019 and 2020 harvest years, respectively. Stubble height was also utilized to vary stover moisture content. A negative linear relationship was established between stubble height and stover moisture content for the early (R2 = 0.76) and late harvest (R2 = 0.91) dates for both years. Stover yield also showed a negative linear relationship (R2 = 0.76) with stubble height over both years. Regardless of the stubble height, the row-crop header collected more stover (p &amp;lt; 0.001) than the ear-snapper header. In 2020, harvested stover ranged from 5.0 to 10.5 Mg ha-1, with ha-1 representing 41% to 85% of the total available stover. In both years, stover ash content was less than 64 g kg-1. Material stored in pilot-scale silos (19 L) was well conserved during anaerobic storage, with average DM losses of 4.8% and 3.4% in 2019 and 2020, respectively. Grain moisture content averaged 23.6% (w.b.) at harvest, and 31.0% (w.b.) after storage as moisture migrated from the moist stover to the drier grain. Harvesting whole-plant corn with a forage harvester had the unwanted effect of reducing the particle size of the grain fraction, which would complicate downstream utilization. However, reducing the harvester cutterhead speed increased the fraction of intact kernels from 47% to 85% by mass. The studied system was a viable alternative to conventional corn grain and stover systems for producing feedstocks for biochemical conversion. Keywords: Ash, Ensiling, Ethanol, Maize.