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Through quantitative statistics and morphological characterization of ceramic fragments for ceramic composite bulletproof insert plates (CCBIPs), distribution characteristics of ceramic fragments within a specific size range were analyzed for different Armor Piercing Incendiary (API) and shot times. To quantitatively evaluate the effect of energy absorption for ceramic plates, a model of energy absorption during penetration for CCBIPs was established based on statistics of the size distribution of ceramic fragments (SDCF). Variation in the SDCF and its influence on energy absorption for CCBIPs were investigated. The results indicate that the distribution feature of ceramic fragments in the range of 0.25–2.25 mm is Gaussian distribution. Compared with Type 56 of API (56-API), ceramic fragments formed by 53-API with higher kinetic energy possess more quantity and more concentrated distribution, whose average equivalence size decreases by 6.5%, corresponding to increasing by 83.9% of estimated energy absorption. Besides, the ability of CCBIPs to resist the third shot is significantly weakened, whose estimated energy absorption decreases by 58.8% compared with the first shot. More concentrated distribution and fewer fragments are formed after the third shot, the average equivalence size of ceramic fragments increases by 6.9%, which may attribute to the micro-cracks induced by the previous two shots.

In studies that assessed the accuracy of implant surgical guides, evaluations were based on the placement position of the implant by using a manufactured surgical guide. However, such assessments could involve errors that may occur during implant placement. Therefore, evaluating the 3-dimensional accuracy of the fabrication of the implant surgical guide itself is not enough. In the evaluation method described in this article, location-related information is obtained by connecting a scan body to the sleeve of the surgical guide instead of directly placing the implant. This helps to evaluate the accuracy of the surgical guide without errors in the placement of an implant.

Modern manufacturing industries are facing challenges in saving energy with less environmental impacts. The Textured cutting tool insert with solid lubrication is attempted by researchers for tribological enhancement and enhance the sustainability in machining. In this work, turning process is performed on Inconel 718 using micro hole textured insert filled with tungsten disulfide (WS2) solid lubricant. The main aim of this investigation is to minimize the power consumption using textured cutting inserts and select appropriate device for measuring power consumption during machining. Three different devices are used to measure the power consumption and the results are analyzed. The results of the investigation revealed that tribological properties are enhanced using micro hole textured cutting inserts with solid lubricant. It is leads to near dry machining and sustainability in manufacturing. The result also pointed out direct measurement of power consumption is accurate and free from errors.

Retrofitting of Engineering marvels/ Structures is very important for preservation of history of mankind. There are various methods available to repair/retrofit the structure depending on type of failure. It was observed that the old structures made up with hard materials like marble, stone etc. which withstand centuries without any sign of failure. But soil underneath the structure is changing day to day due to change in presence and location of water and other physical factors around the structure. This may lead to failure of structure. Pin-pilling is one of the most efficient and economical methods out of several methods available to retrofit the soil underneath the foundation. Piles having diameter less than 30 mm are considered as pin piles. Due to some limitations it is difficult to insert pin piles under the foundation. This paper deals with the study of exact location of insertion of pin piles around the vicinity of existing foundation. A physical model was prepared in lab to simulate the site conditions in which soil is prepared with its natural density and loaded with hydraulic jack and effect of edge distance (Distance of center of pile from edge of foundation) is analyzed as X/B ratio and a notable increase in bearing capacity of soil was observed.

The objective of this article is to propose a cost model that can be used by any type and size of manufacturing company that uses turning processes, anywhere in the world and that is oriented to the optimization of resources, since it has a direct effect on the environmental and economic impact, by reducing waste, avoiding pollution for society and obtaining a monetary benefit. For this, the model adopted conforms to the practical working conditions and the recommendations of both the tool manufacturer, as well as international standards, to machine AISI 1018 steel, which is one of the most common and used materials in the world, for the manufacture of a great variety of mechanical elements, using the CNMG 12 04 08 insert, on a CNC lathe, which allows precise control of the machining parameters and through which the Taylor constants have been obtained experimentally, the results of which validated are satisfactory and as a preliminary step, to finally determine the minimum cost equation of the turning process, which in turn allows to determine the optimal insert cutting speed, which must be within the recommendations and ranges indicated by the manufacturer and also It is possible to determine the life time of the insert, in order to be able to change the insert in a suitable and timely manner.

To reduce the cost and firing temperature of traditional ZrO2 insert rings, the new ZrO2-SiCw-C (w-whisker) insert ring materials were successfully synthesized using ZrO2, Si, graphite powders as starting materials, and phenolic resin as binder. The effects of amount of Si powder addition (5, 8 and 11 wt%) and firing temperatures (1100 °C, 1200 °C and 1400 °C) on the phase composition, microstructure and properties of as-obtained products have been investigated. The results show that Si reacts with C or CO at high temperature to form SiCw, which intersperses in the ZrO2 material to develop an interlocking network structure, resulting in strengthening effect and leading to an increase in the strength of the composites. The composites have good oxidation resistance due to the formation of some glass film on the sample surface. The optimum firing temperature is 1200 °C, which is much lower than that of pure ZrO2 material (>1700 °C). The as-prepared ZrO2-SiCw-C materials possess good properties, making good prospects for fabricating insert rings of slide plates.

Background Lateral mass screws are the most commonly used fixation technique in the Subaxial Cervical Spine (SCS), their main advantages being that they are easy to insert and safe in their application. Pedicle screws are significantly longer, are quite challenging to insert in most settings and are accompanied by the risk of serious complications such as vascular and neural injuries. We have therefore developed a new technique, which permits safe insertion of long screws in the SCS. Methods A radiological evaluation was carried out to determine the maximum possible insertable screw length in the SCS when using the following techniques: pedicle, lateral mass (Magerl’s) and “Attallah” screws. Scans of 66 cervical spines were analyzed to determine the maximum possible screw lengths of all three screw insertion techniques, based on the standard description through the vertebrae from C3 to C7. Results The maximum possible length of the Attallah screw of 20.7 ± 2.5 mm (mean value ± SD) is only 2.4 mm shorter than the pedicle screw (23.1 ± 1.8 mm) along the SCS. The lateral mass screw is with 10.2 ± 1.3 mm full 12.9 mm shorter than the pedicle screw. Conclusions The maximum possible length of the Attallah screw is close to that of the pedicle screw and significantly greater than that of the lateral mass screw. We provide a fixation method comparable to the pedicle screw in its strength and to the lateral mass screw in its safety.

This article discusses the issue of determining the value the average wall temperature of the plate of a recuperative heat exchanger type “air-to-air” with a corrugated mesh insert based on the results processing the data of a physical experiment to determine the thermohydraulic characteristics such heat exchange surfaces. It has been established that the temperature fi eld of heat exchange surfaces of this type is nonuniform, depends on the conditions of heat exchange and hydraulic regimes of air fl ow. Therefore, the adoption of the arithmetic means value of the measured surface temperatures as the calculated average temperature of the heat exchanger wall entails signifi cant errors in the subsequent processing of experimental data and fi nal the values of the heat transfer coeffi cients, the values the Nusselt criterion and the criterion equations of heat transfer. It is proposed to determine the average value the wall temperature of the heat exchanger based on the results of measurements the wall’s temperatures, the estimate of the coordinates the center of distribution the results of measurements the wall temperatures, the equations of heat balance and heat transfer.

The ballistic performance, and behaviour, of an armour system is governed by two major sets of variables, geometrical and material. Of these, the consistency of performance, especially against small arms ammunition, will depend upon the consistency of the properties of the constituent materials. In a body armour system for example, fibre diameter, areal density of woven fabric, and bulk density of ceramic are examples of critical parameters and monitoring such parameters will form the backbone of associated quality control procedures. What is often overlooked, because it can fall into the User’s domain, are the interfaces that exist between the various products; the carrier, the Soft Armour Insert (SAI), and the one or two hard armour plates (HAP1 and HAP2). This is especially true if the various products are sourced from different suppliers. There are between 30 and 150 individual layers within a typical body armour system, and each of the interfaces between each of those layers will, in some way or another, contribute to the ballistic performance of the system. For example, consider the following interfaces/interlayers: (i) the frictional, sliding, inter-ply surfaces within a soft armour pack, and also between the pack and the carrier, (ii) the air-gaps that may develop within the soft armour pack, (iii) the interconnecting space between the soft armour pack and the hard armour plate, (iv) the nature of the interfaces between adjacent plies of a multiplied backing laminate, even in a highly compressed Ultra High Molecular Weight Polyethylene (UHMWPE) variant, (v) the interlayer between the ceramic and its substrate, within a HAP, and (vi) the geometrical fit between two hard armour plates within a stacked body armour system. This paper will provide a User-friendly overview of all such interfaces and provide unique guidance as to their criticality and influence.

Background Soft tissue balance is important for the success of total knee arthroplasty (TKA). Various types of tensors have been developed for the precise measurement of a gap. We hypothesized that the surface shape of the tensor that contacted the TKA component affected the gap measurement. This study aimed to compare the gaps obtained with flat and insert-shaped surface tensors. Methods Two senior surgeons performed 95 TKAs (Vanguard-PS:55 knees; Persona-PS:40 knees). The joint gap was measured in each static knee flexion status (0°, 30°, 45°, 60°, 90°, 120°, and full flexion). We compared the gaps measured with a flat surface tensor and an insert-shape surface tensor. We defined a significant change as a gap difference of >1 mm with a statistical significance. Results In Vanguard-PS, significant changes were observed at 30° and 45°. In Persona-PS, significant changes were observed at 30°, 45°, and 60°. In both implants, gaps measured with the flat tensor were larger than those measured with the insert tensor at approximately midflexion, and the significant changes disappeared in higher flexion position over midflexion. Conclusions The surface shape of the tensor affected the measurement of midflexion laxity in TKA. When measuring the gap with a flat tensor, the midflexion laxity was overestimated. A tensor with an insert-shaped surface should be used to measure the gap in TKA.

Heat transfer enhancement (HTE) efforts spent during the last half-century have become one of the most important working areas of researchers from both academia and industry. One of the most popular passive methods, with regard to the price-performance ratio, is to place wire coils in a pipe or duct. In this study, the heat and pressure drop characteristics of diamond, triangular, and circular cross-sectional wire coils (DWC, TWC, and CWC) in a square duct were investigated by using the FLUENT program. In addition to the cross-section examination, the thermo-hydraulic behavior of three different pitches (p = 54, 72, and 90 mm) for the specified geometries were also investigated. The Reynolds number was between 4387 and 18,415. The square duct was 1.25 m in length, and was 18 mm in diameter. The results showed that the Nusselt number of CWC, TWC, and DWC were higher than that of a smooth pipe within 38–88%, 37–93%, and 38–98% range, respectively. The friction of CWC, TWC, and DWC was observed to be higher than that of a plain tube within a range of 87–278%, 82–266%, and 107–366%, respectively. The TWC with 90 mm pitch showed the highest heat transfer performance evaluation criteria (PEC) with a performance coefficient of 1.3 at Reynolds number of 4504, whereas the DWC with 54 mm pitch was observed to show the lowest PEC. Thus, the as-obtained PEC, which is 30% higher than that of a plain tube, indicates the prominence and effectiveness of the numerical study in increasing the heat transfer.

The performance of the PVD coated carbide insert with micro-holes is experimentally compared with that of the conventional inserts while machining Inconel 718 under Dry and MQL condition (Canola Oil, 0.25% Gr with Canola Oil). The machining performance of textured tool is found to be relatively good when compared to untextured tool in terms of the cutting force, surface roughness, flank wear and crater wear occurred on the cutting inserts. It is being inferred that Canola oil with 0.25% Gr-nanoparticle has improved the cutting force by 17.39%, decreased the flank wear and surface roughness by 20% and 36.23% respectively while machining with the textured tool.

Bi-2212 is one of the most hopeful superconducting material by virtue of its excellent irreversible field and isotropic electromagnetic characteristic. We developed Bi-2212 insert coil for the sake of testing the uniform performance of the round wire (RW). Some important explorations were made including the preliminary test of coil insulation, sealing and heat treatment. In the end, the insert coil achieved a critical performance of 130 A at 12 T and 4.2 K. The experiment results indicated that Bi-2212 RW had met the future application.

Aims Varus-valgus constrained (VVC) devices are typically used in revision settings, often with stems to mitigate the risk of aseptic loosening. However, in at least one system, the VVC insert is compatible with the primary posterior-stabilized (PS) femoral component, which may be an option in complex primary situations. We sought to determine the implant survivorship, radiological and clinical outcomes, and complications when this VVC insert was coupled with a PS femur without stems in complex primary total knee arthroplasties (TKAs). Methods Through our institution’s total joint registry, we identified 113 primary TKAs (103 patients) performed between 2007 and 2017 in which a VVC insert was coupled with a standard cemented PS femur without stems. Mean age was 68 years (SD 10), mean BMI was 32 kg/m2 (SD 7), and 59 patients (50%) were male. Mean follow-up was four years (2 to 10). Results The five-year survivorship free from aseptic loosening was 100%. The five-year survivorship free from any revision was 99%, with the only revision performed for infection. The five-year survivorship free from reoperation was 93%. The most common reoperation was treatment for infection (n = 4; 4%), followed by manipulation under anaesthesia (MUA; n = 2; 2%). Survivorship free from any complication at five years was 90%, with superficial wound infection as the most frequent (n = 4; 4%). At most recent follow-up, two TKAs had non-progressive radiolucent lines about both the tibial and femoral components. Knee Society Scores improved from 53 preoperatively to 88 at latest follow-up (p < 0.001). Conclusion For complex primary TKA in occasional situations, coupling a VVC insert with a standard PS femur without stems proved reliable and durable at five years. Longer-term follow-up is required before recommending this technique more broadly. Cite this article: Bone Jt Open 2021;2(11):921–925.

Metal injection moulding of miniaturized devices demands unique feedstock materials and mould designs with high dimensional accuracy. In this work, the influences of the powder size and powder content of 17–4 PH stainless steel feedstock and the influence of mould design on the successful production of micro-scaled structures were investigated. Ni mould inserts with high dimensional accuracy and texture sizes of 50–200 μm using a new microtexturing technique were manufactured. 17–4 PH stainless steel feedstocks with powder sizes (D90) of 10 and 22 μm and powder contents of 60 and 65 vol.-% were compounded. The rheological properties of the obtained feedstocks were characterized with a capillary rheometer to assess their flowability. The results showed that 10 μm sized particles caused a slight but not significant increase in the viscosity. The highest viscosity increase occurred when the powder content increased from 60 to 65 vol.-%. Feedstocks with the 10 μm powder particles ensured complete filling within microtextures for all mould variations. However, when using feedstocks with 22 μm particles, the filling capabilities of the 50 and 100 μm microtextures decreased with increasing powder content. The shape retention was better for those micropillars produced with mould inserts with 200 μm cavities than for the micropillars replicated with the inserts having cavities of 50 and 100 μm. The results indicated that the proposed mould insert preparation technique opens new possibilities for mass production using the μMIM process to create micro-scaled components using feedstocks without nanoparticles.

Cannulated screw fixation is widely used in the treatment of femoral neck fractures. During surgery, we often face the situation that a guide wire needs to be adjusted because of poor positioning in the femoral neck. It is difficult to adjust the direction of the guide wire in the neck of the femur due to its elasticity. This study developed a practical technique to adjust the guide wire to the correct position. When the direction of insertion of the guide wire has deviated, first, measure the length of the guide wire. Second, select the appropriate cannulated screw based on the measurement, and screw the cannulated screw in along the direction of the guide wire to Ward's triangle. Then return the guide wire to the front of the cannulated screw. At this time, the cannulated screw can be used as a built‐in guide, and a screwdriver can be used to fine‐tune the position of the screw to the optimal direction under the X‐ray guidance. Finally, the cannulated screw is screwed in in this direction until it passes through the Ward triangle area, and the guide wire is inserted. This technique can help doctors insert a guide wire more quickly and accurately, reducing intraoperative injury and the operation time., This study developed a practical technique to direct the guide wire into the correct position. This technique can help trauma surgeons insert a guide wire more quickly and accurately, reducing intraoperative injury and operation time.

AISI 420 stainless steel is one of the alloys that can be used in various applications due to its malleability, high strength, and weldability. In this study, the effects of cutting parameters (feed rate, depth of cut, and cutting speed) on the surface roughness were investigated during the turning of AISI 420 under dry test conditions using coated carbide and ceramic cutting inserts. Response surface methodology, analysis of variance, and statistical methods of the main effect plot were applied to investigate the effects of input parameters on response values. The results of this study showed that feed rate followed by the depth of cut had the most significant effect on output parameters. According to the experimental data, as the feed rate and depth of cut increase, the surface roughness increases.

Patient-specific total knee arthroplasty (TKA) is a copy of the bony knee morphology based on a pre-op computer tomography (CT). The images are segmented in 3D and software is utilized through a proprietary process to generate individual total knee implants to recreate the articulating surfaces. The distal condylar valgus angle of the prosthesis is matched anatomically to the distal femur and reversely matched on the tibia with a thicker lateral insert. The implant, a set of patient-specific jigs (PSJ), which are 3D printed in nylon, and a detailed surgical plan are sent to the hospital in one box. The system is available with one solid or two separated medial and lateral PE inserts. There is a cruciate retaining (CR) and posterior stabilized (PS) version available, including various insert thicknesses. The system allows the addition of two different cemented stem extensions if needed at the time of surgery.

The article considers the modernized design of the crane running wheel with anelastic insert.The purpose of the study is to substantiate the rational design of the running wheel onthe basis of determining the dynamic forces that occur when moving the truck and the crane bridge.Crane equipment is of great importance for the mechanization of lifting and transportoperations in various industries. Bridge cranes perform various lifting and transport operations.Installation and dismantling of equipment and machines. Also take part in the technologicalprocess of the metallurgical industry.The costs associated with the replacement and restoration of the running wheels are 15-17%of the cost of repairing the entire crane. At the same time more than 90% of crane wheels fail due towear of flanges.The main tasks for the diagnosis of crane wheels and rail tracks are usually solved duringscheduled maintenance by visual inspection of the wheel and rail and identify their wear. But thisdiagnostic tool does not quite satisfy the modern conditions of the cranes, namely, the compatiblecondition of the wheels and rails is not assessed, and it is impossible to carry out such controlconstantly during operation.Mechanisms for moving bridge cranes have several designs. The mechanism for moving thetruck, as a rule, has one drive, which transmits motion to the two drive wheels. The mechanisms ofmovement of the crane can be with the central and separate drive. The mechanisms of movement with the central drive can be with a low-speed transmission shaft, with a high-speed transmissionshaft and with a medium-speed transmission shaft.With this design, the gearbox shafts are connected to the drive wheel shaft by means of aclutch and a transmission shaft. This impairs the operation of the entire mechanism, because thepresence of the transmission shaft increases the complexity of the manufacture of the crane and itsweight and requires a very precise installation.To overcome these shortcomings, a separate drive of the end beams of the bridge is used.If the load on one of the support beams of the bridge is less than on the other, the enginespeed on this support increases and the support begins to run forward relative to the more loadedsupport. But the first engine begins to receive increased load, which is transmitted through themetal structure of the bridge and unloads the engine of the second support, due to which the speedof the first engine decreases and the speed of the second engine increases until they are equalized.Thus, in the process of moving the crane with a separate drive is the redistribution of loadbetween the two engines. Although the scheme of the mechanism with separate drives requires twoengines, two brakes and two gearboxes, it is the cheapest, light weight and easy to manufacture.The design of running wheels of cranes and crane carts should exclude a possibility ofderailment of wheels. To do this, the running wheels have two side flanges - flanges, which serve toguide the running wheels on the rails.The dynamic forces that arise when moving the trucks of cranes are quite large and cannot beignored when designing cranes. Most of all, they are manifested by wear of wheels and rails duringthe occurrence of distortions on the cranes.Thus, improving the performance and operational reliability of crane running wheels is avery important task of modern crane construction.The research technique is based on analytical methods of research of dynamic efforts in themechanism of movement of the truck of the bridge crane. The decision of three mass dynamicschemes of movement of the cargo cart is received.The analysis of the received decisions showed that at application of a running wheel with anelastic insert, dynamic factors at movement of the truck decreases. Dependences for determinationof dynamic forces which arise at movement of a running crane wheel taking into account rigidity ofan elastic ring which is inserted into a running wheel are received. The design and a technique ofcalculation of a running crane wheel with the vulcanized ring are offered.

This paper examines the results of experiments conducted on a glazed solar air heater duct which is modified with an additional rectangular duct insert having perforation on its top surface. This modified rectangular duct of varying height is designed to split the incoming air into the absorber. This is presumed to create a pressure difference above and below the perforated surface that will enhance the convective heat transfer due to the cross-flow effect. It is observed from the experiments that the drop in pressure along the absorber passage decreases with an increase in the height, increase in hole diameter, and the number of rows of the hole. It is established from the experiments that thermal efficiency is found to be maximum for the height ratio (h/H) of 0.66 when compared to height ratios of 0.50 and 0.83, perforated duct inserts. Further, by varying the hole diameter ratio and the number of rows, it is noted that two rows of holes with hole diameter ratio of 0.096 configuration gives the maximum thermal efficiency of 84.8% and thermo-hydraulic efficiency of 81.06%.

Axial braided C/C composite materials are widely applied in the throat insert of solid rocket motors. It is the key for the development and design of solid rocket motors to characterize accurately the macromechanical properties of the materials. The Jones-Nelson model is employed to characterize the constitutive relation of the axial braided C/C composite material in this paper. The Jones-Nelson model is expanded and modified to characterize the C/C composite under complex load conditions. The typical external load tests were carried out to verify the accuracy. On this basis, the deformation features of the axial braided C/C composite throat insert are investigated during the working process of motors, and the strain of the throat insert during the working process is obtained by FEM. The strain and temperature in the outer surface of the throat insert are measured in the ground test of motors and are compared with the numerical results by FEM to verify the accuracy of the model. The results show that the result calculated based on the modified Jones-Nelson model by FEM is in a good agreement with the test result. It shows that the modified Jones-Nelson model can better describe the constitutive relation of C/C composite materials, and it can be promoted to the engineering application of the throat insert of solid rocket motors.

Purpose Present investigation conducts a study on the hydrothermal features of a double flow Parabolic Trough Solar Collector (PTSC) equipped with sinusoidal-wavy grooved absorber tube and twisted tape insert filled with nanofluid. This paper aims to present an effectual PTSC which is comprised by nanofluid numerically by means of finite volume method. Design/methodology/approach The beneficial results such as pressure drop inside the absorber tube, mean predicted friction factor, predicted average Nusselt number and hydrothermal Performance Evaluation Criteria (PEC) are evaluated and reported to present the influences of numerous factors on studied interest outcomes. Effects of different Reynolds numbers and environmental conditions are also determined in this investigation. Findings It is found that using the absorber roof (canopy) can enhance the heat transfer ratio of PTSCs significantly during all studied Reynolds numbers. Also, it is realized that the combination of inner grooved surface, outer corrugated surface and inserting turbulator can improve the thermal-hydraulic characteristics of PTSCs sharply. Originality/value Novel PTSC (N.PTSC) filling with two Heat Transfer Fluids (HTFs), inner and outer surface corrugated absorber tube, absorber roof and inserting twisted tape (N.PTSC.f) has the highest PEC values among all novel configurations along all investigated Reynolds numbers which is followed by configurations N.PTSC with two HTFs and inserting twisted tape (N.PTSC.e), N.PTSC with two HTFs and outer surface corrugated absorber tube (N.PTSC.b) and N.PTSC with two HTFs and inner surface corrugated absorber tube (N.PTSC.c), respectively. N.PTSC.f Nusselt number values can overcome the high values of friction factor, and therefore is introduced as the most efficient model in the current study.

This paper presents a new resistance element welding process capable of producing invisible lap joints between steel-polymer-steel composite laminates. The process involves pre-drilling a flat-bottom hole in each laminate to remove the polymer core and one of the steel sheets, and positioning a cylindrical insert inside the two adjoining holes for subsequent resistance welding. Finite element modeling is utilized to construct the weldability lobe and to identify the parameters that lead to the formation of acceptable joints. Experimental results confirm the applicability of the process to produce invisible lap joints without signs of material protrusions or local indentations resulting from squeezing the polymer out to create contact between the steel sheets. Destructive peel and shear tests allow determining the maximum forces that the joints can safely withstand and comparing their performance against alternative joined by forming lap joints in which the mechanical interlocking is also hidden inside the laminates.

This paper presents a modeling method of cutting force and a combination approach of theory and experimental methods in the determination of cutting force coefficients in the face milling process using a parallelogram insert. By the theoretical method, the cutting forces were modeled by a mathematical function of cutting cutter geometry (Cutter diameter, the number of inserts, the insert nose radius, insert cutting edge helix angle, etc.), cutting conditions (depth of cut, feed per flute, spindle speed, etc.), and cutting force coefficients (shear force coefficients, edge force coefficients). By the theoretical method, the average cutting forces in three directions (feed – x, normal – y, and axial – z) were modeled as the linear functions of feed per flute. By the experimental method, the average cutting forces in these three directions were also regressed as the linear functions of feed per flute with quite large determination coefficients (R2 were larger than 92 %). Then, the relationship of average cutting forces and feed per flute was used to determine all six cutting force coefficient components. The validation experiments were performed to verify the linear function of average cutting forces, to determine the cutting force coefficients, and to verify the cutting force models in the face milling process using a cutter with one parallelogram insert. The cutting force models were successfully verified by comparison of the shape and the values of predicted cutting forces and measured cutting forces. These proposed methods and models can be applied to determine the cutting force coefficients and predict the cutting force in the face milling process using a parallelogram insert and can be extended with other cutting types or other insert types

A common source of reduced productivity and lost work time in the industrial setting is musculoskeletal discomfort in the feet, knees, hips, and low back. Even when working identical job posts, these symptoms can vary widely between employees, and could potentially be caused by intrinsic foot biomechanics coupled with long-term standing activities. Therefore, to prevent injury and reduce daily discomfort, onesize-fits-all approaches such as anti-fatigue mats or off-the-shelf shoe insoles may be less effective than treating each employee’s specific biomechanical traits. The Quadrastep System is a prefabricated, semi-custom shoe insert system that bridges the gap between more expensive, fully customized orthotics and off-the-shelf options. We studied the effectiveness of the system in a large manufacturing plant by assessing and providing Quadrastep inserts to 28 volunteers. After 2 months of daily wear, 94% of these volunteers said they received some benefit from the inserts, while 52% reported full resolution of daily symptoms.

Texturing of cutting tool surfaces is emerging as one of the viable solutions to enhance tribological characteristics during machining. Apart from the cutting regime used, the effectiveness of textured tools also depends on the texture geometries. Accordingly, the present study investigates the effect of four different micro-textures on the rake surface of cutting tool inserts in hard turning of Ti-6Al-4V alloys. It specifically addresses the effect of micro-textures on the tool-chip contact length and chip morphology. This study also compares the experimental tool-chip contact length with a new model proposed for inserts with textures. The effect of different insert texture geometries on chip morphology has been investigated by characterizing the chips produced during the cutting. Further, the effects of texture geometries on the parameters like chip compression ratio and shear angle were examined. A detailed analysis has beeen carried out using inserts with and without micro textures to understand their effect on the mechanics of machining. Quantitative predictions were made on the effectiveness of the texture geometry in reducing the cutting forces and friction during machining.

Purpose This paper aims to numerically investigate the thermal performance evaluation of a microchannel with different porous media insert configurations. Design/methodology/approach Heat transfer and pressure drop of fluid flow through a three-dimensional (3D) microchannel with different partially and filled porous media insert configurations are investigated numerically. The number of divisions and positions of porous material inside the microchannel for 12 different arrangements are considered. A control volume method is used for single-phase laminar flow with the Darcy–Forchheimer model used for the porous media. The geometry of the problem consists of a microchannel with a rectangular cross-section of 0.4 mm × 0.2 mm and length 20 mm, with a stainless steel porous material insert with a porosity coefficient of ε = 0.32 and a Darcy number of Da = 2.7 × 10−4. Findings Numerical results show that when the transverse arrangement is used, as the number of partitions increases, the thermal performance is improved and the heat transfer increases up to 300% compared to that of the plain microchannel. Comparing the obtained results from the microchannels with transverse and longitudinal configurations, at low Reynolds numbers, the transverse arrangement of porous blocks and at high Reynold numbers, the longitudinal arrangement present the best thermal performance which is virtually four times higher compared to the obtained Nu numbers from the plain microchannel. The results show that as the volume of porous material is constant in the cases with various transverse porous blocks, the pressure drop is not changed in these cases. Also, the highest thermal performance ratio is when the porous material is placed along the walls in a longitudinal direction. Originality/value To the best knowledge of the authors, in the previous research, the effect of the arrangement and location of the porous medium in the transverse and longitudinal direction in the microchannel and their effect in different states on the behavior of flow and heat transfer has not been numerically investigated. In this study, the porous media configuration and its placement in a 3D microchannel were numerically studied. The effect of porous material layout and configurations in different longitudinal and transverse directions on the pressure drop, heat transfer and thermal performance in the 3D microchannel is investigated numerically.

In this work the effect of geometrical parameters of the twisted tape insert on heat transfer and flow characteristics of SiO2/H2O nanofluid flow heat exchanger tube has been investigated experimen...

A coaxial insert with distributed impedance corrugations for cavities of subterahertz second-harmonic gyrotrons is investigated. The insert is designed to serve multiple functions: suppression of all first- and second-harmonic competing modes, attainment of high peak power, and widening of continuous frequency tunability. In the design study, advantages are taken of distributed shallow and deep corrugations of the coaxial insert. The multifunctional corrugated insert for a coaxial cavity is used to improve performance of a second-harmonic 527-GHz gyrotron. It is shown that the designed insert enables stable single-mode operation of this gyrotron with peak output power of 66 W and frequency bandwidth of 3 GHz. The sensitivity of the gyrotron performance to machining errors in the multifunctional corrugated insert is discussed.

Screws are often used to connect 3-D printed parts to other objects. When screwing directly into printed plastic, the reliability is limited, and the connection can wear out over time. For more reliable connections, standard metal nuts are often inserted into slots designed into the object. This article presents an approach where nuts and other ferromagnetic components are integrated directly into the part while printing it. Our prototype machine is a modified Prusa-I3 fused filament fabrication printer with an electromagnetic pick and place tool. We introduce augmented slicing software, where the user can insert generic component models from a library and place them at arbitrary positions in the object. Cavities for the components and additional G-code commands for robotic placing are automatically generated and sent to the printer. A printed component tray is attached to the printbed, allowing different part configurations for each print. The pick and place unit is controlled by our OctoPrint plugin OctoPNP.

We present a design overview of the MIT 1.3-GHz LTS/HTS NMR magnet (1.3G) with a newly designed 835-MHz REBCO insert (H835) as a replacement for the 800-MHz REBCO insert (H800) that was damaged when it quenched during operation in 2018. The new H835 is designed to contribute 19.6 T in a background field of 10.93 T by an LTS NMR magnet that normally rated at 11.74 T (500 MHz): combined, 1.3G generates a total field of 30.53 T corresponding to a proton resonance frequency of 1.3 GHz. H835 is designed to operate stably while meeting 1.3G design constraints. We have also designed H835 to protect it from permanent damage in an improbable event like a quench. Key design features are: 1) a single-coil formation, composed of 38 stacked metal-co-wound no-insulation and 2 stacked no-insulation double-pancake coils, all with mechanically improved cross-over sections; 2) enhanced thermal stability; and 3) reduced current margin with a detect-and-heat method. This paper includes: 1) electromagnetic and mechanical design of H835; 2) cryogenics overview; 3) quench protection strategy; and 3) discussion on the next steps to successfully complete 1.3G.

This work is devoted to the formulation and search of an analytical solution for the problem of the interaction of a rigid cylindrical body and a pipe with an inner coating in the case when the cylinder is placed inside such a pipe. It is assumed that the pipe coating can have a strong nonuniformity, and its thickness depends on the longitudinal coordinate. A special approach used in this work allows obtaining analytical solutions in which functions related to the properties and profile of the coating are separated by separate terms and factors. This allows us to provide efficient calculations even in cases where coating characteristics are described by complex functions. Other known methods lead to significant calculation errors.

Support insert run-flat tire is a kind of safety tire based on common tire structure. It has the advantages of simple structure, easy disassembly and strong bearing capacity. However, when driving under zero-pressure condition, it can not meet the requirements of heavy load, high mobility and long-distance. Aiming at this problem, the finite element model is established. The load and contact patch characteristics of the model are simulated by ABAQUS. The radial stiffness curve and the contact pressure distribution under zero-pressure are obtained. The results show that the radial stiffness curve presents a certain nonlinearity in the sidewall loading stage. When the insert contacts the tire, it is approximately linear. The contact pressure distribution cloud diagram under zero-pressure condition shows that there is warpage. The tire test bench was set up and the relevant test scheme was formulated. The radial stiffness curve and the footprint of the support insert run-flat tire under zero-pressure condition were obtained. The research results show that the simulation and test results are in good agreement. This research is of great significance to the performance analysis of whole support insert run-flat tire under zero- pressure condition.

This investigation is aimed at the design and optimization of boron arsenide insert structures embedded in the heat spreader of a 3-D Integrated Circuit (IC). The inserts are distributed in three m...

Recently, this kind of agriculture is in danger of threatening its future since it depends upon industrial agriculture to provide the bulk of the food we eat. In high-voltage applications, the three-phase Gas Insulated Busductor (GIB) is considered to be the most important to fulfill high demand. Due to numerous flaws like as delamination, protrusion, etc. induced during the switching process, GIB is shown to have insulator failures. Those flaws have a significant impact upon the distribution of the electric field across the distance and hence on the entire GIB system, which causes enormous economic losses. This paper provides a post-type spacer for a three-phase GIB of delamination with a Functionally Degraded Material (FGM), an additional particle introduced at high voltage for the analysis of the adverse behavior of the spacer and subsequent insertion of metal inserts minimize the stress of the electronic field. By doping it with varying permittivity values to provide uniform electric field stress using a Finite element procedure, FGM is spatially dispersed with various filling materials. Simulation with planned spacer is performed as faults at various voltages and FGM grades with delamination and particle. With the insertion of the metal insert in the FGM spacer type postal insert, the influence of aluminum particles with varying delamination sizes is reduced and the findings obtained are given.

Aim:-The Present study is focused on the comparison of performances of Titanium carbide(TIC) and Uncoated carbide tool inserts with CNC turning of HCHC D2 Steel for minimizing surface roughness and maximizing material removal rate. Materials And Methods:- Machining of HCHC D2 steel material was compared with Titanium carbide(TIC) and Uncoated carbide tool inserts. It was divided into two groups of 27 samples each. The samples were machined with two different tool inserts one was control group and other was experimental group. Results:- Surface roughness was decreased and material removal rate was increased when machining was done with TIC carbide compared to HSS tool insert (P=0.028).Conclusions: It is concluded that the surface roughness was decreased and material removal rate was increased when TIC carbide tool insert was used for machining.

Aim: This research is about comparing the performance of poly-crystalline diamond (PCD) insert and uncoated cemented carbide insert for improving the material removal rate (MRR) in CNC turning. Materials and Methods: The material investigated in this research was SS316L. PCD insert was set as the experimental group and uncoated insert was set as the control group. The cutting parameters employed in this process were cutting speed, feed rate and depth of cut. Totally 27 samples per group were machined by using the selected parameters. Results: The mean MRR value obtained for the PCD tool is 0.22593 g/s, whereas it is 0.07600 g/s for the uncoated tool. The significance value obtained among the experimental group and control group is 0.000 (p

Purpose Eye plaques are widely used for ocular melanoma and provide an effective alternative to enucleation with adequate tumor control. A COMS plaque utilizes a Silastic insert for precise positioning of the radioactive seeds with respect to the scleral surface of the eye; however, due to manufacturing variability, the insert may unintentionally increase or decrease the distance between the sources and tumor. The purpose of this work is to provide guidance in measuring and identifying outliers in Silastic inserts. The importance of regular quality assurance (QA) is illustrated in an experience where a systematic problem was detected and the manufacturer's 22‐mm mold was corrected. Methods A detailed description of the molds and manufacturing process used to produce Silastic inserts is provided, including photographs of the process steps. The variability in Silastic insert production was evaluated by measuring the thickness of 124 Silastic inserts. An estimate of how the observed Silastic thickness discrepancies impact the dose to the tumor and critical eye structures was performed using homogeneous dose calculations. A standard QA protocol was developed to guide the clinical user. Results Thickness of the measured Silastic inserts ranged from 1.22 to 2.67 mm, demonstrating variation from the 2.25 mm standard. Six of the 22‐mm inserts were outliers (Δthickness >3 standard deviations) and were excluded from the statistics. The outliers were investigated with the help of the manufacturer, who discovered that a systematic error was accidentally introduced into the 22‐mm mold. Conclusions Due to manufacturing errors or variability, the Silastic inserts used in COMS eye plaques may be thicker or thinner than the design standard. Such variations may impact tumor control or increase the risk of normal tissue side effects. A standardized QA program is recommended to detect variations and communicate unusual findings to the manufacturer.

Titanium alloys are widely used in many areas, such as aerospace, biomedical, and automotive industries, due to their excellent chemical and physical properties. However, its difficult-to-machine characteristic causes various problems in the machining process, such as serious tool wear and elastic deformation of workpieces. To achieve high efficiency and quality of machining titanium alloy materials, this paper conducted an experimental research on the high-speed milling of TC11 titanium alloy with self-propelled rotary milling cutters. In this paper, the wear mechanism of self-propelled rotary milling cutters was explored; the influence of milling velocity was analyzed on cutting process, and the variation laws with the change in milling length were obtained of milling forces, chip morphology, and machined surface quality. The calculation method of self-propelled rotary velocity was proposed, based on the experimental research. The results showed that in the early and middle stages of milling, the insert coating peeled off evenly under the joint action of abrasive and adhesive wear mechanisms. As the milling length increased, the dense notches occurred on the cutting edge of the cutter, the wear mechanism converted gradually into fatigue wear, and furthermore, coating started peeling off the cutting edge with the occurrence of thermal fatigue cracks on the insert. As the milling length was further extended, the milling forces tended to intensify, the chip deformation worsened, and the obvious cracks occurred at the bottom of chips. The increase in milling velocity intensified the friction between chips and self-propelled rotary milling cutters, and decreased the ratio of self-propelled rotary velocity to milling velocity. This caused the drop in cutting performance of cutters and the growth in tool wear rate.

Textured cutting insert filled with solid lubricants is one of the best alternative cooling methods in metal cutting industries. The problem associated with textured insert is the supply of solid l...

Purpose Rapid tooling (RT) integrated with additive manufacturing technologies have been implemented in various sectors of the RT industry in recent years with various kinds of prototype applications, especially in the development of new products. The purpose of this study is to analyze the current application trends of RT techniques in producing hybrid mold inserts. Design/methodology/approach The direct and indirect RT techniques discussed in this paper are aimed at developing a hybrid mold insert using metal epoxy composite (MEC) in increasing the speed of tooling development and performance. An extensive review of the suitable development approach of hybrid mold inserts, material preparation and filler effect on physical and mechanical properties has been conducted. Findings Latest research studies indicate that it is possible to develop a hybrid material through the combination of different shapes/sizes of filler particles and it is expected to improve the compressive strength, thermal conductivity and consequently increasing the hybrid mold performance (cooling time and a number of molding cycles). Research limitations/implications The number of research studies on RT for hybrid mold inserts is still lacking as compared to research studies on conventional manufacturing technology. One of the significant limitations is on the ways to improve physical and mechanical properties due to the limited type, size and shape of materials that are currently available. Originality/value This review presents the related information and highlights the current gaps related to this field of study. In addition, it appraises the new formulation of MEC materials for the hybrid mold inserts in injection molding application and RT for non-metal products.

In the milling process of water chamber head, the service life of cemented carbide inserts is low, and inserts are prone to premature breakage and impact fracture. Dynamic cutting force is one of t...

The coating on carbide insert surface can effectively reduce the transfer of cutting heat to the inside of the insert, improve the surface wear resistance and cutting performance, and ensure the se...

Spacer fabrics are 3D fabrics comprising of two outer fabric layers that are joined together and kept apart by an insert of spacer yarns, mostly monofilaments. This creates a ventilated layer of air, allowing heat and moisture to escape. Material types and the surface characteristics of the layers influence the thermoregulation properties of the spacer fabrics. In this study, Warp Knitted Spacer Fabrics (WKSF) were designed with polyester multifilament in face and back surface layers and are linked by middle layer made of polyester monofilament. Three-factorial Box and Behnken experimental design was used and the effects of different polyester filament denier combinations of face, middle and bottom layers and the porosity of the fabric on the thermoregulation properties were analysed. The analysis of variance (ANOVA) and response surface design (RSM) were used for the optimization of porosity and thermal properties of the WKSF. The experimental result indicates that among the three layers of polyester WKSF, the face layer has exceptional influence on all the responses and the bottom layer has trivial or no impact.

Turning operation is one of the primary machining operations and enhanced machining performance is obtained by its process parameters. In turning process, heat is generated and it must be removed from the machining zone. Now a days, hydrocarbon oil based cutting fluid is used and it generates environmental issues as well as operator health issues. Recently, textured cutting tool inserts are attempted towards sustainable machining. In this work, turning process is carried out on aluminium-metal matrix composite (Al-MMC) with micro hole textured cutting tool inserts. Micro hole texturing involves various parameters such as hole diameter, hole depth and pitch between the holes. The main aim of this work is to analyze the effect of micro hole design parameters on machining performance. The input parameters include diameter of the micro hole, pitch between hole and hole and depth. Process outcomes include surface roughness, tool wear and power consumption. The experiments are performed based on L9 Taguchi orthogonal array. The result revealed that micro hole textured tools with solid lubricant embedded cutting inserts and its design parameters influence machining performance. Texture with solid lubricant could act as alternative to hydrocarbon oil based cutting fluid and also chip breaker.