Motor Grade Research Articles

2D Path Following Control of Motor Graders

Optimal ground conditions in mining are crucial for operational efficiency and safety. Motor graders play a crucial role in achieving precise grading of passages; however, unlike many other mining vehicles, they have not yet been commercially automated. The redundant kinematics of motor graders, including articulation, front axle steering, and blade operations, pose significant challenges for automation. This research explores path following with a 2D kinematic model of motor graders and uses simulation to evaluate and compare the performance of these controllers in terms of step response and operational effectiveness. To address kinematic redundancy, two methods are proposed: Rear Offset Control, which defines the articulation angle using a lateral offset between the front and rear axles, and Single Track Control, which utilizes steering redundancy to adapt existing automation approaches to articulated vehicles. Simulation tests were conducted using two controllers: a Feedback Linearized PD controller (FBL+PD) and a Feedback Linearized Model Predictive Controller (FBL+MPC). Both were tuned for optimal performance on a step input path, with performance assessed based on Root Mean Square Error (RMSE) and control effort. This work introduces two methodologies—Rear Offset Control and Single Track Control—for autonomous motor grader operation. These were implemented with FBL+PD and FBL+MPC controllers on a 2D kinematic model. Future research will focus on dynamic modeling, implementing a Non-Linear Model-Predictive Controller, refining tuning methodologies for Feedback Linearized systems, and integrating these approaches with live vehicles.

Outcomes of Common Peroneal Nerve Decompression.

Common peroneal nerve (CPN) neuropathy is the most common lower extremity mononeuropathy. When delayed or no recovery from CPN neuropathy is suspected, surgical CPN decompression (CPND) is considered to relieve symptoms. This study aimed to evaluate patient outcomes post-CPND performed by a single surgeon at a tertiary medical center. Patient outcomes after CPND performed by a single surgeon were reviewed. Motor, sensation, and pain scores post-CPND were assessed in 47 of the 46 patients. Patient demographics, including age, concomitant morbidities, time from injury to surgery, and body mass index (BMI), were also analyzed for correlations with outcomes after CPND by logistic regression. 29/34 patients with impaired motor function improved by at least one motor grade, 19/42 with altered sensation reported restored normal sensation, and 31/37 reported improved pain after CPND. No correlation of patient demographic factors with motor or pain improvement after CPND was observed. However, a BMI greater than 29.15 and a time between injury and surgery exceeding 506 days were associated with lower odds of reporting restored sensation. Operative decompression of CPN neuropathy improves objective motor scores and subjective sensation and pain scores.

Analisis Biaya Operasional Alat Berat pada Pekerjaan Timbunan

Heavy equipment plays an important role in construction work, especially road construction work. The advantage of using heavy equipment is that it can get the job done faster. Improper use of heavy equipment will cause losses, so an analysis of operational costs is very necessary. Accurate and complete calculation of heavy equipment operational costs will help companies to make decisions, especially from a financial perspective. The purpose of this study was to determine the analysis of the operating costs of heavy equipment, and to know the proper and proper handling of heavy equipment. Cost analysis on heavy equipment is expected to provide benefits to be able to plan heavy equipment management in a coordinated, effective and sustainable manner. This research was conducted on the project Peningkatan Jalan Alun-Alun Suka Makmue-Jalan Lingkar Timur Ibu Kota Tahap II which is located in the district Nagan Raya. This study uses a qualitative method with a descriptive approach, namely research that seeks to describe problem solving based on data that will be obtained in the field. This research was conducted on four types of heavy equipment, namely excavators, motor graders, vibrator rollers and water tanker trucks. The results of the calculation of the operational cost analysis of excavator heavy equipment Rp. 738,617 per hour, motor grader Rp. 572,401 per hour, vibrator roller Rp. 499,735 per hour and water tanker truck Rp. 348,859 per hour. From the results obtained, it shows that for heavy equipment excavators and motor graders there has not been a return on capital, while for heavy equipment vibrator rollers and water tankers there has been a return on capital. So for heavy equipment, vibrator rollers and water tanker trucks, it is feasible to replace them with new tools

Влияние химического фактора на безопасные условия труда машинистов дорожно-строительной техники

The article considers current issues of the impact of harmful and hazardous factors of the production environment and working process on the working conditions of employees of the road construction industry. In particular, potentially negative chemical factors at the workplace of drivers of road construction machinery have been identified; the extent of their impact on the personnel has been determined based on the special assessment of working conditions. The list of harmful substances and mixtures in the air of the working area of the drivers of road construction machinery has been established. The protocols of chemical factor measurement and assessment and the cards of special assessment of working conditions at 16 workplaces of the drivers of various road construction machinery have been analyzed. Based on the comparative analysis and its graphic visualization, specific working conditions at the workplace of drivers most exposed to the adverse impact of chemical factors have been detected. The largest emissions of harmful chemicals are primarily specific for the workplaces of drivers of highly specialized road equipment, i.e., pavers, self-propelled rollers, and motor graders. Therefore, at the workplace of a driver of a GS-1402 motor grader, the maximum permissible concentration of chemical elements is exceeded by 11 % for NO2 and СО combination. For asphalt paver drivers, when employing Vogele and DC 191.504.02 pavers, the shift-average maximum permissible concentrations of harmful substances are exceeded by 9.67 % and 4.33 % respectively for the mixture of limiting aliphatic hydrocarbons C1–C10. The study of chemical impact on road construction workers can aim at the detailed investigation of working conditions and their improvement by the development of workflow organization at all stages of motor road construction. The special assessment of working conditions can be used as a tool to develop approaches to security and occupational safety management in road construction.

Optimizing the Use of Heavy Equipment on Earthworks on the Syamsudin Noor Banjarbaru Airport Ring Road

Earthworks on the Syamsudin Noor Banjarbaru Airport Ring Road Construction Project in 2019 include activities of digging, moving, displacing, leveling, forming the road body and compacting embankment soil in a loose volume of 375,000.00 m3 in solid with laterite soil type (chosen fill) . The heavy equipment used will be calculated for productivity, tool requirements and operational costs for each tool, namely: Komatsu PC 200 Excavator, Nissan Hino FM 260 JD 16 m3 Dump Truck, Catterpillar D6R Bulldozer, Catterpillar 120 G Motor Grader and Vibratory Roller Bomag Komatsu BW 217 D. Analysis and calculations using data analysis methods include material analysis, work implementation methodology, equipment production calculations, tool requirements, and equipment operating costs to complete the work. The results of the analysis show that Excavator productivity is 150.70 m3/hour, number of 3 units, operational costs Rp. .77m3/hour, number of 2 units, operational costs Rp. 1,617,521,830.24, Motor Grader productivity 1,392 m3 / hour, quantity 1 unit, operational costs Rp. 247,830,796, 12 and Vibratory Roller productivity 241.07 m3 / hour, number of 2 units, operational costs Rp. 757. 806,142.93. with a total cost of using heavy equipment for earthworks of Rp. 8,481,158,634.27

Predictor of Postoperative Ambulatory Recovery in Metastatic Spinal Cord Compression with Delayed Surgical Timing and Progressive Paraplegia

OBJECTIVETo analyze preoperative predictors of ambulatory recovery after surgical treatment in metastatic spinal cord compression(MSCC) patients with delayed surgical timing and progressive paraplegia. METHODSWe reviewed patients with a preoperative lower-extremity motor grade of ≤ 3 and surgical timing ≥ 48h after the non-ambulatory status. The recovery group(group R) and non-recovery group(group NR) were classified according to ambulation assessment during follow-up. The data on patient demographics, origin of the primary tumor, pre- and postoperative chemotherapy and radiation therapy, surgical procedures, Tokuhashi score, Karnofsky score, preoperative lower-extremity motor grade, and surgical timing were collected for analyzing predictors of postoperative ambulatory recovery. RESULTSOf the 55 patients, 24(43.6%) were group R and 31 patients were group NR. The preoperative motor grade of the lower extremities was the only predictive factor (P<0.05). The mean hip flexor and knee extensor motor grades in group R were 2.0±1.0 and 2.4±1.1 respectively, while in group NR, they were 1.2±1.0 and 1.3±1.0. The odds ratios for failing to regain ambulatory ability were 12.6 in the knee extensor and 4.8 in the hip flexor when the motor grades 0-2 and 3 groups were compared. The rescue ratio of the preoperative hip flexor and knee extensor motor grade 0-2 group were 34.1% and 21.2%, grades 3 group were 71.4% and 77.3%, respectively. CONCLUSIONThe significant predictive factor for ambulatory recovery was the preoperative lower-extremity motor grade. The preoperative knee extensor motor grade was identified as a more important factor than hip flexor motor grade in predicting ambulatory recovery.

Digitalization of The Construction Industry with BIM and 3D Machine Control Integration for Construction Performance Improvement.

The Government of the Republic of Indonesia through Presidential Regulation Number 100 of 2014 and Presidential Regulation Number 117 of 2015 aims the construction of the 2770 km Trans Sumatra Toll Road from Bakauheni to Banda Aceh to be fully constructed by 2024. There are two key stages in the project phase, i.e planning and construction stages. The planning stage is carried out using the Building Information Model (BIM), while the construction phase integrates BIM with 3D-Machine-Control. This study is conducted in Trans Sumatera Pekanbaru - Bangkinang’s Toll Road with 40 kilometers long as a study case. The data acquisition methodology is conducted using qualitative and quantitative methods throughout the field’s experiments. This study conducted the examination of the LiDAR UAV digital survey’s accuracy, the BIM implementation on Level of Development (LOD) 200, 300, and 400, verification of the usage of Motor Grader with 3D-Machine-Control efficiency in elevation cutting works, and the application of Vibro Compactor with 3D-Machine-Control for improving the accuracy of soil compaction on the subgrade and base course. The results showed that the topographic data from UAV LiDAR are accurate within LE90 accuracy with 0.176 cm. The optimalization of 3D-Machine-Control could carry out the earthworks as similar as design also can be used as quality and quantity control. The time efficiency which obtained from implementing Motor Grader with 3D-Machine-Control for elevation cutting application is 47%.

Optimization of design parameters of the vibration protection system of a motor grader seat with quasi-zero stiffness

BACKGROUND: Vibrations occurring during operation of land transport-technological machines deteriorate the quality of control, reduce the productivity of the work performed, adversely affect the health of machine operators. In order to reduce the impact of vibrations on the operators, vibration protection systems of the cab and seat are used.&#x0D; AIMS: For practical application of the developed design of the passive vibration protection system of the motor grader operators seat on the basis of a parallelogram mechanism, tensile spring, cable and rollers, it is necessary to develop an algorithm for optimizing the values of design parameters.&#x0D; METHODS: The mean square value of seat acceleration in a stationary reference frame, determined as a result of simulation of the motor grader motion over a set of stochastic microprofiles of the support surface with various characteristics and velocities, was used as an optimization criterion. Comprehensive simulation mathematical model of a motor grader with cabin vibration protection supports and vibration protection system of a seat was used. All parameters of the optimization algorithm and model were divided into fixed, random and varying ones. The latter include a number of dimensions of the parallelogram mechanism of the seat vibration protection system, the coefficient of viscous friction of the mechanisms shock absorber, the height of the quasi-zero stiffness zone. The dependence of the criterion on the design parameters of the seat vibration protection mechanism, which has an implicit pattern and is determined by means of a simulation mathematical model, served as the target function. Boundary conditions were imposed on a number of parameters to ensure the operability of the mechanism, manufacturability of its parts as well as ergonomic considerations. Optimization of the values of the varying parameters was performed with the simplex method. At the same time, a part of the parameters unambiguously influencing the value of the target function was preliminarily maximized or minimized within the boundary ranges.&#x0D; RESULTS: An algorithm for assignment and optimization of design parameters of the vibration protection system of a motor grader seat with quasi-zero stiffness is developed, one of the key features of which is the possibility to adjust the vibration protection system of the seat to the weight of the current operator. Examples of algorithm application are given.&#x0D; CONCLUSIONS: The algorithm makes it possible to determine the optimal values of design parameters of the seat vibration protection system based on a parallelogram mechanism such as: the dimensions of the parallelogram mechanism, including the attachment points of rollers and cable, the coefficient of tensile spring stiffness, the coefficient of viscous friction of a shock absorber, the parameter of adjusting the mechanism to the weight of the current operator. The key feature of the developed vibration protection system and the optimization algorithm of its design parameters is the possibility of adjustment to the weight of the current operator.

Concordance between needle electromyography and manual muscle test findings for muscles with motor grades 0 and 1.

When it is difficult to determine whether a muscle is grade 0 or 1, manual muscle test (MMT) accuracy can be further improved by using needle electromyography (EMG) as a supplementary and confirmatory examination tool. To evaluate concordance between needle EMG and MMT findings for key muscles with motor grades 0 and 1 on the International Standards of Neurological Classification of Spinal Cord Injury (ISNCSCI) examination, and to potentially improve the prognosis for grade 0 muscles with proven muscle activity based on needle EMG findings. A retrospective analysis. Inpatient tertiary rehabilitation facility. Not applicable. One hundred seven patients with spinal cord injury (SCI) admitted for rehabilitation (n = 1218 key muscles, grades 0 or 1). Inter-rater reliability between MMTs and needle EMG was analyzed using Cohen's kappa coefficient (κ). A Mantel Haenszel linear-by-linear association chi-square testwas used to determine whether the presence of motor unit action potentials (MUAPs) in muscles graded 0 on the initial MMT at admission was associated with MMT grades at discharge and readmission. Moderate-to-substantial agreement between needle EMG and MMT findings was observed (κ = 0.671, p < .01). Concerning key upper and lower extremity muscles, moderate and substantial agreement was identified, respectively. The lowest agreement was noted for C6 muscles. During follow up, 68.8% of muscles with proven MUAPs showed improved motor grades. At initial assessment, distinguishing between motor grades 0 and 1 is imperative because motor grade 1 muscles are more likely to have a better prognosis for improvement. Moderate-to-substantial agreement was observed between MMT and needle EMG findings. The MMT is a reliable method of muscle grading, yet needle EMG may be of value in certain clinical situations to evaluate for the presence of MUAPs when evaluating motor function.

The method of ensuring the road-holding ability of the motor grader during the performance of technological operations

Problem. The article proposes a method of ensuring course stability of a motor grader during technological operations. As a system for adapting the motor grader to changing operating conditions, it is proposed to simultaneously use the mechanism for turning the front wheels in the horizontal plane and the mechanism for tilting the front wheels in the vertical plane. Goal. Development of a method of adapting a motor grader to changing external load conditions during technological operations. Methodology. As a criterion for adaptation, the index of permissible deviation of the motor grader from the planned trajectory of movement at the distance of the given length was used. Originality. The proposed criterion depends on the type of technological operation performed and the type of parameters of the developed environment. Results. The method of ensuring road-holding ability of the motor grader involves the analysis of the movement of the machine on the work site and the development of recommendations for the effective use of the adaptation system. Practical value. On the basis of the obtained results of experimental studies, a graphical and analytical analysis was performed, which made it possible to provide recommendations on the choice of turning angles and inclination of the wheels as a function of the angle of the transverse inclination of the support surface and the coefficient of adhesion.

Signal device for motor grader

Problem. Automated machines play an important role in modern construction, improving productivity, quality and safety. A signal device for road construction machines plays an important role in ensuring the efficient performance of road works. It relieves the driver of the need to continuously monitor the devices and controls of the motor grader. In this work, a signal device was proposed for continuous monitoring of the devices and controls of the motor grader. Goal. As a result of the analysis, the purpose of the study was highlighted: to design a signal device for a motor grader. Job tasks: to design a signal device for continuous monitoring of the motor grader's devices and controls. Methodology. Аutomation of construction and road machines is carried out mainly in three areas, which provide control of the spatial position of the working bodies of machines, optimization of the most energy-intensive modes of machine operation and the creation of a laser-based integrated automated process control system in construction. It was decided to design a signal device with different tones and sound effects Results. The result of the study is the design of a signal device for continuous monitoring of devices and controls of a motor grader, which makes it easy to determine the state of the controlled controls of the motor grader, even when performing several functions simultaneously. Originality. The originality lies in the fact that the signal device has different tones and sound effects (trill, siren), which make it easy to determine the state of the motor grader's controlled controls. Practical value. The signal device performs three functions: signal the height position of the blade relative to the plane necessary for the transportation of the motor grader; signal the critical angle of the blade turn relative to the direction of the motor grader; signal the critical transverse inclination of the blade.

Studying the impact of the angle of motor grader blade installation in the plan on its maximum force, considering the random process of occurrring difficulty in overcoming the obstacle

Problem. The operation of a motor grader takes place in different soil conditions, and individual work operations differ from each other in the patterns of external loads and form differently the load on the components of the working bodies. Goal. The goal is to determine the effect of the angle of installation of the motor grader working body (blade) on the maximum force exerted by the working body when it hits an obstacle that is difficult to overcome for different categories of soil. Methodology. In the process of studying the state of the matter, the method of analysis was used, and in theoretical studies – the analytical method, which is based on the theory of interaction of working bodies with the developed environment, as well as the provisions of the theory of reliability, probability and mathematical statistics. Results. As a result of studying the process of cutting, stopping, and hitting an obstacle, we have assessed the load of the working body. Originality. A dependence has been proposed that allows us to estimate the influence of the angle of capture of the motor grader main blade in the plan on the maximum force exerted by its working body. This takes into account the randomness of the process of appearing a difficulty to overcome an obstacle. It was found that with an increase in the angle of the blade in the plan, the maximum force on the latter increases when it encounters an obstacle. The influence of the soil category on the maximum force exerted by the working body is investigated. The maximum force reaches its highest value in the third soil category when the blade is installed directly. Practical value. It is planned to confirm the obtained dependence of the maximum force on the angle of the blade grip during real work operations by a motor grader on soils of various categories.

Study of the influence of pollution particles of 5 мkм and less on the anti-wear properties of the working fluids of hydraulic drives of construction and road machinery

Problem. An analysis of the impact of contamination of the working fluid on the state of the hydraulic equipment elements of construction and road machines, the efficiency of their operation, and also the use of the coefficient of anti-wear properties to determine the service life of working fluids is presented. The equation of the dependence of the wear rate of hydraulic equipment elements on the coefficient was obtained. Operational tests of the GR165 motor grader were also carried out, which showed that the service life of the Hydro HV 46 working fluid according to the coefficient of anti-wear properties is approximately 1184 machine hours. Methodology. In the process of studying the state of the matter, the method of analysis was used, and in theoretical studies – the analytical method, which is based on the theory of interaction of working bodies with the developed environment, as well as the provisions of the theory of reliability, probability and mathematical statistics. Results. The research results showed that coefficient Kj of anti-wear properties can be the only integral indicator of the quality of working fluids and determine their service life in hydraulic drives of Construction machines. Originality. The equation was obtained for the rate of wear, taking into account the interaction of charged particles of wear with friction surfaces. For the stationary friction mode, the equation of the balance of the contamination particles that are part of the working fluids of the hydraulic actuators and the rate of wear of friction vapor were obtained. The use of KJ coefficient as an indicator of working fluids of hydraulic drives of construction machines is presented. Practical value. The research results showed that the coefficient Kj of anti-wear properties can be the only integral indicator of the quality of working fluids and determine their service life in hydraulic drives of Construction machines.

Optimization method for main parameters of vibration protection system in motor grader seat with quasi-zero static characteristic

Introduction. One of the urgent tasks facing the developers of land transport and technological machines is to reduce the vibration effects on the human operator. Vibration impacts are caused mainly by the interaction of the working bodies with the working environment and the running equipment of machines with the microrelief of the supporting surface on which the machine moves. To reduce vibration impacts, vibration protection systems of the cab and operator’s seat are used. The designs of vibration protection systems of seats with the effect of quasizero stiffness are promising. The design of a passive vibration protection system of an operator’s seat based on a parallelogram mechanism, which makes it possible to provide the specified effect of quasi-zero stiffness, is proposed. For practical application of the developed vibration protection system of a seat, it is necessary to solve the problem of assignment and optimization of its main design parameters.Materials and methods. RMS vertical acceleration of a seat in a stationary coordinate system was taken as the target function for optimizing the design parameters of the vibration protection system of a seat. For the developed calculation scheme of the seat vibration protection system based on a parallelogram mechanism, independent design parameters that influence the mean square vertical acceleration of the seat were identified. To reduce the dimensionality of the problem, some of the parameters were bound by algebraic dependencies, or fixed. The need to reduce the number of independent varying parameters was due to the relatively long simulation time of the individual process of moving the machine along the microrelief of the supporting surface using the developed complex simulation mathematical model of a motor grader with vibration-proof supports of the operator’s cabin and with a vibration-proof mechanism of the operator’s seat. The horizontal length of the parallelogram link, the ductility factor of the damper mechanism, and the horizontal dimension from the rotation axis to the limiting rollers of the mechanism were selected as independent.Results. A methodology for selecting and optimizing the design parameters of the vibration protection mechanism, presented in the form of a flowchart, which includes the stage of local optimization of the viscosity factor of the damper and the horizontal dimension from the axis to the limiting rollers by the Simplex method, has been developed. Obtaining each individual value of the target function in the local optimization was performed by processing the results of discrete values of seat acceleration obtained by simulating the movement of the machine on a simulation mathematical model. Examples of the application of the developed technique with different sets of initial data are given.Discussion and conclusions: The application of the developed technique makes it possible to unambiguously determine the values of design parameters of the vibration protection system based on the parallelogram mechanism, including geometric dimensions, the viscosity factor of the damper, as well as, as secondary output parameters, the stiffness and dimensions of the tensile spring of the mechanism.

Association of upper-limb neurological recovery with functional outcomes in high cervical spinal cord injury.

High cervical spinal cord injury (SCI) results in complete loss of upper-limb function, resulting in debilitating tetraplegia and permanent disability. Spontaneous motor recovery occurs to varying degrees in some patients, particularly in the 1st year postinjury. However, the impact of this upper-limb motor recovery on long-term functional outcomes remains unknown. The objective of this study was to characterize the impact of upper-limb motor recovery on the degree of long-term functional outcomes in order to inform priorities for research interventions that restore upper-limb function in patients with high cervical SCI. A prospective cohort of high cervical SCI (C1-4) patients with American Spinal Injury Association Impairment Scale (AIS) grade A-D injury and enrolled in the Spinal Cord Injury Model Systems Database was included. Baseline neurological examinations and functional independence measures (FIMs) in feeding, bladder management, and transfers (bed/wheelchair/chair) were evaluated. Independence was defined as score ≥ 4 in each of the FIM domains at 1-year follow-up. At 1-year follow-up, functional independence was compared among patients who gained recovery (motor grade ≥ 3) in elbow flexors (C5), wrist extensors (C6), elbow extensors (C7), and finger flexors (C8). Multivariable logistic regression evaluated the impact of motor recovery on functional independence in feeding, bladder management, and transfers. Between 1992 and 2016, 405 high cervical SCI patients were included. At baseline, 97% of patients had impaired upper-limb function with total dependence in eating, bladder management, and transfers. At 1 year of follow-up, the largest proportion of patients who gained independence in eating, bladder management, and transfers had recovery in finger flexion (C8) and wrist extension (C6). Elbow flexion (C5) recovery had the lowest translation to functional independence. Patients who achieved elbow extension (C7) were able to transfer independently. On multivariable analysis, patients who gained elbow extension (C7) and finger flexion (C8) were 11 times more likely to gain functional independence (OR 11, 95% CI 2.8-47, p < 0.001) and patients who gained wrist extension (C6) were 7 times more likely to gain functional independence (OR 7.1, 95% CI 1.2-56, p = 0.04). Older age (≥ 60 years) and motor complete SCI (AIS grade A-B) reduced the likelihood of gaining independence. After high cervical SCI, patients who gained elbow extension (C7) and finger flexion (C8) had significantly greater independence in feeding, bladder management, and transfers than those with recovery in elbow flexion (C5) and wrist extension (C6). Recovery of elbow extension (C7) also increased the capability for independent transfers. This information can be used to set patient expectations and prioritize interventions that restore these upper-limb functions in patients with high cervical SCI.

Resect, rewire, and restore: Nerve transfer salvage of neurological deficits associated with soft tissue tumors in a retrospective cohort series at a tertiary reconstructive center

We aimed to explore the effectiveness of nerve transfer as an intervention to restore neurological deficits caused by extremity tumors through direct nerve involvement, neural compression, or as a consequence of oncological surgery. A retrospective cohort study of consecutive cases was conducted, including all patients who underwent nerve transfers to restore functional deficits in limbs following soft tissue tumor resection. The threshold for a successful nerve transfer was a BMRC motor grade of 4/5 and sensory grade of 3-3+/4 with protective sensation. In total, 29 nerve transfers (25 motor and 4 sensory) were completed in 11 patients, aged 12-70 years at referral, over a 6-year period to 2020. This included 22 upper limb and 3 lower limb motor nerve transfers. The timing of delayed nerve transfer reconstructions was 1-15 months following primary oncological resection, with immediate simultaneous reconstructions performed in 4 cases. The threshold for success was achieved in 82% of upper limb and 33% of lower limb motor nerve transfers, while all sensory transfers were successful in restoring protective sensation. Nerve transfer surgery, a well-established technique in restoring deficits following traumatic nerve injury, is further demonstrably relevant in extremity oncological reconstruction, especially as it can be performed remotely to the tumor location or resection site and introduces a healthy nerve or fascicle to rapidly reinnervate distal muscles without sacrificing major function. This study further illustrates the importance of early recognition and referral to specialist services where multi-disciplinary surgical resection and reconstructive planning can be conducted. IV Clinical Case Series.

146 Functional Priorities in High Cervical Spinal Cord Injury: Implications for Upper Limb Nerve Transfer Surgery

INTRODUCTION: High cervical spinal cord injury (SCI) results in complete impairment in upper limb function. Nerve transfer is an innovative reinnervation strategy for upper limb reanimation following SCI. However, the impact of upper limb motor recovery on the degree of long-term functional outcomes remains unknown. METHODS: A prospective cohort of high cervical SCI (C1-C4) patients enrolled in SCI model systems (SCIMS) was included. Baseline neurological examinations and functional independence measures (FIM) in eating, bladder-function, and transfers (bed/wheelchair/chair) were evaluated. At one-year follow-up, functional independence was compared in patients who gained recovery (motor grade &gt;=3) in C5-elbow flexion, C6-wrist extension, C7-elbow extension, and C8-finger flexion. A multivariable logistic regression evaluated the impact of motor recovery on functional independence on composite outcome of feeding, bladder-function, and transfers. RESULTS: Between 1992-2016, 405 high cervical SCI patients were included. At baseline, 97% patients had impaired upper limb function with inability in all functions. At one-year follow-up, the largest proportion of patients gaining independence in eating, bladder-function, and transfers had recovery in C8-finger-flexion and C6-wrist-extension. C5-elbow-flexion recovery had lowest translation into functional independence. Patients who achieved C7-elbow-extension were able to transfer independently. On multivariable analysis, C8-finger-flexion recovery had 12-times higher odds (p=0.004) and C6-wrist-extension recovery had 7-times higher odds (p=0.04) of gaining functional independence in composite outcome. Age &gt;=60 years and motor complete SCI (ASIA-A-B) were associated with reduced odds of gaining independence. 8% patients improved ASIA grades from baseline to 1-year. CONCLUSIONS: Following cervical SCI, C8-finger-flexion and C6-wrist-extension recovery can maximize functional independence. Recovery of C7-elbow-extension can increase transfer capability. This information may prioritize reinnervation strategies for individualized decision-making for nerve transfers in high cervical SCI.

Paper 03: Suprascapular Neuropathy: Two Distinct Presentations and Outcomes of Decompression

Objectives: Suprascapular neuropathy due to nerve compression or tension at the suprascapular notch is an uncommon source of shoulder pain and rotator cuff weakness with recent increased recognition and treatment. Long considered an elusive diagnosis, work-up can be lengthy and patients may experience treatment delay. We aimed to review presentation patterns and outcomes of arthroscopic suprascapular nerve decompression in a predominantly young and active military population. Methods: The surgical databases of two surgeons were queried for patients treated with arthroscopic suprascapular nerve decompression at the suprascapular notch from 2013 to 2021. Patient data, presentation and workup findings, and outcome measures were collected through review of the electronic medical record. Primary outcome measures were rate of return to active-duty military service, shoulder abduction and external rotation strength, and VAS pain scores. Secondary outcome measures were American Shoulder and Elbow Surgeons (ASES) Shoulder Score, Visual Analogue Scale (VAS), and Single Assessment Numerical Evaluation (SANE) score. Results: Twenty-five patients were identified. Average age was 26.6 years and follow-up 17.9 months (4-62 months). There were two distinct primary presentation types in this cohort: the chief complaint was pain in 13 patients (52%) and weakness in 12 (48%). Supraspinatus and/or infraspinatus atrophy was present on MRI in 10/12 patients with weakness and 0/13 with pain. Electromyography was positive in 9/12 with weakness and negative when obtained in 5 patients with pain. Ultrasound-guided suprascapular nerve injection was performed in 10/13 with pain and provided mean 91% symptom relief. Patients with pain had longer duration of pre-operative symptoms (22.2 [±13.1] vs. 10.3 [±13.6] weeks). Postoperatively, the pain group had significant improvement in VAS scores (6.2 [±1.6] to 1.0 [±0.9]), while the weakness group had significant improvement in abduction and external rotation motor grading (3.7 [±0.7] to 4.7 [±0.4] and 3.3 [±0.8] to 4.4 [±0.6] respectively). Return to duty or sport was 92% at a mean of 14.6 (±9.3) weeks. Conclusions: In this young, active cohort, suprascapular neuropathy presented with one of two distinct primary presenting complaints: pain or weakness. Given different expected work-up findings, categorizing patients into one of these two groups may be beneficial in effectively diagnosing and treating suprascapular neuropathy. Outcomes after arthroscopic suprascapular nerve release at the suprascapular notch predictably led to successful pain relief and strength improvement in patients presenting with pain and weakness respectively. [Table: see text][Table: see text]

Modeling Productivity Reduction and Fuel Consumption in Open-Pit Mining Trucks by Considering the Temporary Deterioration of Mining Roads through Discrete-Event Simulation

Open pit mining is based on dynamic operations within the open pit, with the haulage operation being the most decisive in terms of the cost and the overall productivity of the operation. A vital aspect for the success of the haulage operation are the conditions of the roads, which change over time due to wear and tear. The present work aims to model and to evaluate the effect of temporal deterioration affecting mining roads in an open pit mining operation through rolling resistance, using the discrete event simulation (SED) tool to evaluate two key aspects of the operation: productivity and fuel consumption. Additionally, to reverse road deterioration, the assignment of a grader with a variable frequency of use will be modeled through a parallel model. The case study is a 5 km road with a slope of 9.5%, a fleet of 10 trucks, and their capacities of 300 tons, loaded in a 24 h simulation model. The results show that not considering road deterioration can mean an overestimation of productivity of up to 600 Ton/hr, and an overconsumption of 78%. The application of a motor grader could decrease the negative effects of roads deterioration, which depends on the frequency of its assignment. The results show that for the rate of productivity and fuel consumption for every hour of frequency that the motor grader does not do road maintenance, the production loss is 600 tons, and the fuel consumption increases by approximately 1800 L in a day.

Analysis and Optimization of Heat Dissipation Module in the Motor Grader Engine Compartment

Abstract To solve the problem of heat reflow in the fan rotation center of the forced convection cooling system in the engine compartment, this study established a calculation model of the external flow field of the engine compartment’s cooling module. It then used the CFD numerical simulation method to calculate and analyze the heat flow characteristics of the existing radiator and compared these with the experimental results. Accordingly, the region where the heat reflux occurred and the reason for the heat reflow were found. The existing heat dissipation scheme was recalculated by using the secondary heat dissipation model, and an optimized and improved scheme was proposed to introduce a deflector cone structure to eliminate heat reflow. The research results showed that the secondary heat dissipation model could more accurately describe the heat reflow problem of the engine compartment, the heat flow organization of the improved structure was more reasonable, and the temperature distribution was more uniform. Moreover, the theoretical heat dissipation effect of the improved structure was more than 10% higher than that of the existing structure.