Repair Part Research Articles

Repair part service level differentiation based on holding other parts shortage costs

PurposeThe article addresses the optimization of safety stock service levels for parts in a repair kit. The work was undertaken to assist a public transit entity that stores thousands of parts used to repair equipment acquired over many decades. Demand is intermittent, procurement lead times are long, and the total inventory investment is significant.Design/methodology/approachDemand exists for repair kits, and a repair cannot start until all required parts are available. The cost model includes holding cost to carry the part being modeled as well as shortage cost that consists of the holding cost to carry all other repair kit parts for the duration of the part’s lead time. The model combines deterministic and stochastic approaches by assuming a fixed ordering cycle with Poisson demand.FindingsThe results show that optimal service levels vary as a function of repair demand rate, part lead time, and cost of the part as a percentage of the total part cost for the repair kit. Optimal service levels are higher for inexpensive parts and lower for expensive parts, although the precise levels are impacted by repair demand and part lead time.Social implicationsThe proposed model can impact society by improving the operational performance and efficiency of public transit systems, by ensuring that home repair technicians will be prepared for repair tasks, and by reducing the environmental impact of electronic waste consistent with the right-to-repair movement.Originality/valueThe optimization model is unique because (1) it quantifies shortage cost as the cost of unnecessary holding other parts in the repair kit during the shortage time, and (2) it determines a unique service level for each part in a repair kit bases on its lead time, its unit cost, and the total cost of all parts in the repair kit. Results will be counter-intuitive for many inventory managers who would assume that more critical parts should have higher service levels.

Service and inventory model for maintenance workshop in the short cycle operation region: Agent-based simulation approach

Tools used in the North Sea region has a high cycle and come very often to maintenance workshop to be checked, repaired if needed and prepared for the next operations. The availability of spare parts at the workshop plays a significant role to keep the flow time as short as possible and meet such high-cycle operations. Supplying spare parts from the best-cost countries to the North Sea region with about one-year lead time makes the situation more critical and the economic order quantity and reorder point need to be found. However, having inventory at the workshop and ordering a batch of spare parts increases operational expenditures. Moreover, frequent supplies increase the environmental impacts of shipping CO2 and spare scrap rates, whereas repairing the used spare parts and reusing them again can offer a more sustainable solution. Therefore, the purpose of this paper is to develop a simulation model that can quantify the cost and benefits of reusing repaired spares compared to supplying newly built spares from the best-cost countries. To achieve this purpose, a case study has been implemented on a specific maintenance workshop within the North Sea region and the entire tool repair and spare part supply operations are conceptualized and modelled with the help of the simulation modelling approach. Two scenarios have been simulated: (1) the maintenance workshop fully depends on supplying newly built spares from the best-cost countries with no inventory stock or spare reuse, and (2) the Maintenance workshop is primarily dependent on repaired spares with an optimal level of spares stock. The simulation results, from the studied case, support the second scenario where a repair path cycle is introduced to the maintenance workshop, as a 78% reduction in lead times, a 116% improvement in worker utilization, a 73% reduction in crowding levels, a 52% reduction in scrap rate, and a potential profit increase of roughly three million NOK (20%). Therefore, it can be concluded that a local repair service is required to keep maintenance workshops in high-cycle regions at high-performance levels.

Development of Economic Effect Model for Field Operation Data Analysis Works

Purpose: This paper presents a method to estimate the economic effects of field operation data analysis works. In particular, the presented models quantitatively measure the economic effects based on the availability, failure rate, and identification of frequently failing items identified from field operation data analysis works.BRMethods: To achieve this purpose, the presented models estimate the economic effects from three perspectives, namely value increase through realization of availability, value increase according to the realization of calculation of repair part requirements, and effect of quality improvement of frequently failing items.BRResults: The proposed models were validated by applying them to predefined operating scenario targeting a virtual weapon system. As a result, it was confirmed that the three proposed economic effect models calculated the economic effects for each weapon system.BRConclusion: Several models for quantitatively measuring the effectiveness of field operation specifications analysis were presented, and their effectiveness was verified through case studies. This study is unique because similar research has not been conducted in the defense domain thus far.

Assessment of the universality of duplex stainless steel powder in laser additive repair based on Schaeffler diagram

The type and quantity of repair materials used in ocean or field environment is unclear. This study investigated the effective methods for evaluating the universality of a specific powder for multiple materials using a self-made universal duplex stainless steel powder (UDSS) as the object and tensile strength (σ) of the additive repair part in the normal direction of the interface as the index. Based on the Schaeffler diagram, the equivalent distances of Cr and Ni were used to characterize the chemical composition difference between the material to be repaired and the UDSS powder, and the angle θ was used to characterize the difference in microstructures. Three models, σ-(Cr eq , Ni eq ) , σ-ρ equivalent distance linear, and σ -( ρ,θ ) polar coordinate models, were proposed for predicting the strength of the additive repaired part. These models were verified using the results of repair tests on five substrates. The mean prediction error, pf, of the σ -( ρ, θ ) polar coordinate model was minimum, that is, approximately 9.68%. Under the conditions of this study, the maximum normal strengths of the repaired specimen interface in the normal direction were 689, 704, and 957 MPa in the austenite, ferritic, and ferrite + austenite regions, respectively, thus proving the universality of the UDSS powder used. This study provides a novel and a reliable method for evaluating the universality of UDSS powder for laser-additive repair. The relationship between the tensile strength and evolution of the microstructure, chemical composition, and microhardness near the interface is discussed.

Regulated macrophage immune microenvironment in 3D printed scaffolds for bone tumor postoperative treatment.

The 3D printing technique is suitable for patient-specific implant preparation for bone repair after bone tumor resection. However, improving the survival rate due to tumor recurrence remains a challenge for implants. The macrophage polarization induction to M2-type tumor-associated macrophages (TAMs) by the tumor microenvironment is a key factor of immunosuppression and tumor recurrence. In this study, a regenerative scaffold regulating the macrophage immune microenvironment and promoting bone regeneration in a dual-stage process for the postoperative treatment of bone tumors was constructed by binding a colony-stimulating factor 1 receptor (CSF-1R) inhibitor GW2580 onto in situ cosslinked hydroxybutylchitosan (HBC)/oxidized chondroitin sulfate (OCS) hydrogel layer covering a 3D printed calcium phosphate scaffold based on electrostatic interaction. The hydrogel layer on scaffold surface not only supplied abundant sulfonic acid groups for stable loading of the inhibitor, but also acted as the cover mask protecting the bone repair part from exposure to unhealthy growth factors in the microenvironment at the early treatment stage. With local prolonged release of inhibitor being realized via the functional material design, CSF-1R, the main pathway that induces polarization of TAMs, can be efficiently blocked, thus regulating the immunosuppressive microenvironment and inhibiting tumor development at a low therapeutic dose. At the later stage of treatment, calcium phosphate component of the scaffold can facilitate the repair of bone defects caused by tumor excision. In conclusion, the difunctional 3D printed bone repair scaffold regulating immune microenvironment in stages proposed a novel approach for bone tumor postoperative treatment.

A two-dimensional maintenance optimization framework balancing hazard risk and energy consumption rates

Numerous power assets, such as power cables and refrigerator, have inevitably confronted with severe energy consumption problems. An essential topic in maintenance engineering of such assets is to balance energy consumption mitigation and malfunction risk control, such that to reduce production/delivery losses. This paper established a novel proactive maintenance framework, which arranges two dimensions of control limits to control maintenance frequencies: (a) operational age and (b) consumption severity to guide repair and spare part replacement. The energy consumption process is structured by a Semi-Markov chain. The asset is preventively replaced upon a certain operational age, or when the unit time energy consumption reaches a pre-specified threshold, given that the time to scheduled age-based replacement is greater than a threshold. The maintenance optimization model is formulated, followed by an in-depth exploration of its analytical structures. The superior performance of the proposed framework over conventional maintenance policies is demonstrated by a numerical experiment on high-voltage power cables.

Meniscus Repair Part 2: Technical Aspects, Biologic Augmentation, Rehabilitation, and Outcomes.

Multiple meniscal repair techniques exist, and successful healing and excellent patient outcomes have been reported with a variety of all-inside and open techniques. Increased awareness and recognition of root tears and meniscocapsular separations are topics of recent interest. The ideal treatment of these injuries remains uncertain, and definitive recommendations regarding their treatment are lacking. Postoperative protocols regarding weight bearing and range of motion are controversial and require future study. The role of biologics in the augmentation of meniscal repair remains unclear but promising. An evidence-based individualized approach for meniscal repair focusing on clinical outcomes and value is essential.

STRUCTURAL ANALYSIS OF BULKHEAD PATCH REPAIR DUE TO HEAT DAMAGE

The integrity of the aircraft structure after a permanent repair requires thorough engineering analysis. In this study, the aircraft’s defective Bulkhead was damaged due to heat exposure and repaired with a patching technique known as a bulkhead patch repair. The study aimed to analyse the repair carried out using numerical calculation and finite element analysis. The first result of the numerical calculation shows that the repair part (stainless steel) will restore the original part (AA7050) strength capability. The second result from the LS-Dyna analysis shows that heat damage had caused the material (AA7050) strength to deteriorate significantly. The final loads testing using LS-Dyna analysis on components shows the patch repair scheme conducted was capable of strengthening the damaged part by transferring the applied loads to repair part. The outcome of this study justified that for better maintenance action (structural integrity consideration), the damaged Y453 Bulkhead needed to be replaced instead of conducting permanent repair.

Способ восстановления вала редуктора с применением упрочненной ремонтной детали

Способ восстановления вала редуктора с применением упрочненной ремонтной детали

Hubungan Pelaksanaan Penggunaan APD terhadap Kecelakaan Kerja di JOB Pertamina Talisman Jambi Merang

This research is focused to approach at the relationship between the implementation of personal protective equipment (PPE) to safety programme with employee, where PPE is used as a last resort in an effort to protect workers if the effort to control the elimination of danger sources, equipment substitution, engineering and administration but the potential risk is still relatively high. This research is focused on associative descriptive with correlation approach, which uses a questionnaire of 80 employees in the JOB Pertamina Talisman Jambi Merang production department engaged in the oil and gas industry located in Bayung Lencir, South Sumatra Province. The results of this study use a bivariate analysis test looking for the relationship between the application of personal protective equipment (PPE) with workplace accidents at the job accident on the crew driling the repair part of the well maintenance at the RPS 05 rig, PT.Pertamina EP Asset 1 Field Jambi. The study found that there was a significant relationship between the variables of K3 inspection and personal protective equipment (PPE) against work accidents. with a value (r) of 0.722 which means a significant relationship between the commitment to carry out K3 inspection and personal protective equipment (PPE). (PPE).

The rabbit brachial plexus as a model for nerve injury and repair Part 1: Anatomic study of the biceps and triceps innervation.

Animal models can be helpful in evaluating new surgical strategies for brachial plexus reconstruction. While several groups have already used the rabbit brachial plexus to model injury, reports conflict in anatomic detail and do not identify a nerve-muscle pair to measure motor function recovery after reconstruction. The purpose of the current study is to describe the innervations of the biceps and triceps muscles in rabbits, which are both amenable to study in brachial plexus injury models. Thirteen rabbits weighing 2-2.5 kg were anesthetized. Six rabbits were sacrificed and dissected using loupe and microscope magnification to understand the overall morphology of the brachial plexus. Seven rabbits underwent electrophysiologic investigation. A bipolar nerve stimulator was used to systematically stimulate the roots, trunks and divisions, and nerve branches of the rabbit brachial plexus and compound muscle action potential was used to record muscle response. Nerve length and width measurements were not recorded. Roots contributing to the brachial plexus were C5, C6, C7, C8, and T1. In contrast to other anatomical studies, T2 did not contribute to the brachial plexus. The triceps was innervated by the radial nerve, which received contributions from C6 (1.6 mA), C7 (1.9 mA), C8, and T1 (12.2 mA).The biceps had dual innervation (proximally and distally). The proximal branch received contributions from C6 (3.5 mA) and C7 (5mA). The distal portion was innervated by a branch from the median nerve, which received innervation from C6, C7, C8, and T1. The overall structure of rabbit brachial plexus is described and innervation of the biceps and triceps is described in detail. This anatomic investigation will form the basis of a future brachial plexus model of injury and repair.

Experimental study on slipping behavior of patch plate repair part with corrosion damage using high strength bolted friction joint

Experimental study on slipping behavior of patch plate repair part with corrosion damage using high strength bolted friction joint

The mechanics of urethral closure, incontinence, and midurethral sling repair Part 3 surgical applications (1990-2016).

Part 3 briefly summarizes further development in midurethral sling (MUS) instruments and technique following the 1990 prototype operations, then critically examines the whole MUS surgical methodology, 1990 to present day. The aim is to identify positive and negative aspects of these methodologies which can be usefully applied to improve current MUS surgery. ANIMAL EXPERIMENTS: 1987-1988 proved that a collagenous neoligament could be formed by implantation of a tape. There was a wide variation in tissue reaction to implanted tapes. Inflamamatory tissue reaction was very different from bacterial infection and was safe even when a sinus is formed. MUS METHODOLOGY: The key factor in avoiding major vessel and nerve injuries is to penetrate the perianal membrane with scissors, insert the applicator. Importantly, this reveals any bleeding which could otherwise accumulate in the Space of Retzius and only be controlled by digital pressure. The balance between too tight (retention) and too loose (incontinence) is analyzed in terms of the exponential relationship between urethral diameter and urine flow; why elastic tapes are more likely to cause post-operative urinary retention; how to minimize retention by tightening against an indwelling No18 Foley catheter; the importance of routinely repairing the distal closure mechanism with purse string suture to external ligaments, fascial layer of vagina; why minislings avoid most of the serious MUS complication; why a tensioned minisling allows greater precision when tightening the sling and how anchors and individually knitted tapes give hope that tape erosions may decrease.

Painting completion with generative translation models

Image completion has always been an important research area of image processing. With the continuous development of the deep learning model in recent years, further progress has been made in the repair of images. In this paper, we focused on realistic and painting portrait data, studied on semantic inpainting techniques based on regional completions, and proposed an improved generative translation model. Through the context generation network and the image discriminator network, a patch image is generated which should keep consistency between the hole and the surrounding area. Then the completed part will be processed according to the scene structure of the image through the style translation network to ensure the consistency between the generated area and the whole image, which means the repair part can better adapt to the style, texture, and structure of the artistic work. Experiments have shown that our method could achieve good results in the completion of realistic and painting portraits, and it also provided some reference for restoration and identification of art works.

PARP-1 protects against colorectal tumor induction, but promotes inflammation-driven colorectal tumor progression

Colorectal cancer (CRC) is one of the most common tumor entities, which is causally linked to DNA repair defects and inflammatory bowel disease (IBD). Here, we studied the role of the DNA repair protein poly(ADP-ribose) polymerase-1 (PARP-1) in CRC. Tissue microarray analysis revealed PARP-1 overexpression in human CRC, correlating with disease progression. To elucidate its function in CRC, PARP-1 deficient (PARP-1-/-) and wild-type animals (WT) were subjected to azoxymethane (AOM)/ dextran sodium sulfate (DSS)-induced colorectal carcinogenesis. Miniendoscopy showed significantly more tumors in WT than in PARP-1-/- mice. Although the lack of PARP-1 moderately increased DNA damage, both genotypes exhibited comparable levels of AOM-induced autophagy and cell death. Interestingly, miniendoscopy revealed a higher AOM/DSS-triggered intestinal inflammation in WT animals, which was associated with increased levels of innate immune cells and proinflammatory cytokines. Tumors in WT animals were more aggressive, showing higher levels of STAT3 activation and cyclin D1 up-regulation. PARP-1-/- animals were then crossed with O6-methylguanine-DNA methyltransferase (MGMT)-deficient animals hypersensitive to AOM. Intriguingly, PARP-1-/-/MGMT-/- double knockout (DKO) mice developed more, but much smaller tumors than MGMT-/- animals. In contrast to MGMT-deficient mice, DKO animals showed strongly reduced AOM-dependent colonic cell death despite similar O6-methylguanine levels. Studies with PARP-1-/- cells provided evidence for increased alkylation-induced DNA strand break formation when MGMT was inhibited, suggesting a role of PARP-1 in the response to O6-methylguanine adducts. Our findings reveal PARP-1 as a double-edged sword in colorectal carcinogenesis, which suppresses tumor initiation following DNA alkylation in a MGMT-dependent manner, but promotes inflammation-driven tumor progression.

鉄筋コンクリートの打継部に形成するマクロセルへの腐食速度解析モデルの適用

Many reinforced concrete structures in Japan are aging. A reasonable and durable design by the numerical analysis is necessary to extend the service life of concrete structures. Based on the above background, this paper is applied the macrocell corrosion rate analysis model whom authors proposed to the members with a joint. First the model is constructed. The input data is an anode polarization curve, a cathode polarization curve, a polarization resistance, and an electrical resistance of mortar. On the other hand, the output data is a total corrosion current. Next, an analytical value is compared with the experiment value while using the mortar specimen that imitated the patch repair part. As a result, it can be cleared that the model is appropriate. Finally, the effect of the macrocell countermeasures method with the spray of the silane type surface penetrant on the joint is verified by this model. Thus, it can be confirmed that when the electrical resistance at the joint is large, the corrosion rate becomes low analytically.

Estimation of the structural integrity of a runway repaired by compliant polymer concretes under thermomechanical loading conditions

When repair materials are applied for runway maintenance, possible material failures due to the differences in material properties and excessive shrinkage of the repair material needs to be investigated. Moreover, the repair part is subjected to various mechanical loadings, which should be taken into account for determining the best repair material. In this study, we investigate a real-time in-situ health monitoring system, which is composed of two Fiber Bragg Grating (FBG) optic sensors, to monitor the strain variations that are induced by environmental conditions and material shrinkage. The repair process with compliant polymer concrete (72:20:08(T)) was carried out at the Gimpo international airport (Korea) during the summer season. To consider the effect of mechanical loading on stress distribution in the materials, several dynamic analyses are also carried out by using the finite element analysis method. Based on the results, the feasibility and reliability of the health monitoring system using FBG optic sensors are verified.

The Importance of Imaging Technology

The Importance of Imaging Technology

Controlling Repair Part Costs Through Supply Chain Management

Controlling Repair Part Costs Through Supply Chain Management

EVALUATION OF EFFECT ON REPAIR OF SECTION REPAIR METHOD OF CONSTRUCTION BASED ON REINFORCING BARS MASS DECREASE RATE OF THE LONG-TERM EXPOSURE TEST BODY

This paper reports the results of outdoor exposure test on the repair performance on corrosion of reinforcing bar in salt containing concrete by various repairing materials. When there is much chlorination amount of material in the concrete, effect on repression of the reinforcing bars corrosion by the repair method of construction can't be expected very much. When the repair of the section repair part is done, that countermeasure is important from showing a tendency of progressing in the part of the boundary remarkably as for the reinforcing bars corrosion after the repair. If chipping isn't taken to the back of the reinforcing bars, the effect of rust is prevented material, section repair material, When chlorination amount of material increases, corrosion spreads out in surface direction and depth direction as well.