Assembly Machine Research Articles

The prevalences and levels of occupational exposure to dusts and/or fibres (silica, asbestos and coal): A systematic review and meta-analysis from the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury

The prevalences and levels of occupational exposure to dusts and/or fibres (silica, asbestos and coal): A systematic review and meta-analysis from the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury

Automated assembly of high-density carbon fiber electrode arrays for single unit electrophysiological recordings

Objective. Carbon fiber (CF) is good for chronic neural recording due to the small diameter (7 µm), high Young’s modulus, and low electrical resistance, but most high-density carbon fiber (HDCF) arrays are manually assembled with labor-intensive procedures and limited by the accuracy and repeatability of the operator handling. A machine to automate the assembly is desired. Approach. The HDCF array assembly machine contains: (1) a roller-based CF extruder, (2) a motion system with three linear and one rotary stages, (3) an imaging system with two digital microscope cameras, and (4) a laser cutter. The roller-based extruder automatically feeds single CF as raw material. The motion system aligns the CF with the array backend then places it. The imaging system observes the relative position between the CF and the backend. The laser cutter cuts off the CF. Two image processing algorithms are implemented to align the CF with the support shanks and circuit connection pads. Main results. The machine was capable of precisely handling 6.8 μm carbon fiber electrodes (CFEs). Each electrode was placed into a 12 μm wide trenches in a silicon support shank. Two HDCF arrays with 16 CFEs populated on 3 mm shanks (with 80 μm pitch) were fully assembled. Impedance measurements were found to be in good agreement with manual assembled arrays. One HDCF array was implanted in the motor cortex in an anesthetized rat and was able to detect single unit activity. Significance. This machine can eliminate the manual labor-intensive handling, alignment and placement of single CF during assembly, providing a proof-of-concepts towards fully automated HDCF array assembly and batch production.

IgG Fc-binding protein positively regulates the assembly of pore-forming protein complex βγ-CAT evolved to drive cell vesicular delivery and transport

Cell membranes form barriers for molecule exchange between the cytosol and the extracellular environments. βγ-CAT, a complex of pore-forming protein BmALP1 (two βγ-crystallin domains with an aerolysin pore-forming domain) and the trefoil factor BmTFF3, has been identified in toad Bombina maxima. It plays pivotal roles, via inducing channel formation in various intracellular or extracellular vesicles, as well as in nutrient acquisition, maintaining water balance, and antigen presentation. Thus, such a protein machine should be tightly regulated. Indeed, BmALP3 (a paralog of BmALP1) oxidizes BmALP1 to form a water-soluble polymer, leading to dissociation of the βγ-CAT complex and loss of biological activity. Here, we found that the B.maxima IgG Fc-binding protein (FCGBP), a well-conserved vertebrate mucin-like protein with unknown functions, acted as a positive regulator for βγ-CAT complex assembly. The interactions among FCGBP, BmALP1, and BmTFF3 were revealed by co-immunoprecipitation assays. Interestingly, FCGBP reversed the inhibitory effect of BmALP3 on the βγ-CAT complex. Furthermore, FCGBP reduced BmALP1 polymers and facilitated the assembly of βγ-CAT with the biological pore-forming activity in the presence of BmTFF3. Our findings define the role of FCGBP in mediating the assembly of a pore-forming protein machine evolved to drive cell vesicular delivery and transport.

Research on the Vibration Response of an Aircraft Gun Muzzle Based on Nonlinear Finite Element

The muzzle vibration response of an aircraft gun is one of the key factors affecting the firing accuracy of the aircraft gun. In order to study the muzzle vibration response of an aircraft gun, based on the basic theory of the nonlinear finite element method, the nonlinear finite element dynamics simulation model is established by considering the nonlinear factors which are the contact and collision between the gun aircraft and the cradle, the contact and collision between the elevating gear arc and gear, and the slide clearance between the aircraft gun and the cradle, etc. The muzzle vibration response is characterized by the linear displacement and linear velocity of the center point of the aircraft gun, and its dynamics is obtained through numerical calculation and simulation. The correctness of the dynamics simulation model of the aircraft gun muzzle vibration is verified by setting up verfication bench. The results show that the established nonlinear finite element dynamic simulation model can be used to predict the muzzle vibration response of the aircraft gun, and at the same time, by changing the slide clearance between the aircraft gun and the cradle, the effect of clearance on the muzzle vibration response is investigated. Additionally, it can be seen that reducing the slide clearance can improve the firing accuracy of the aircraft gun while ensuring the machining assembly and mechanism movement.

Development of elements of computer programming in component cross technologies of manufacturing mechanical equipment in engineering

Purpose. Development of elements of programming on equipment with numerical software control in end-to-end technologies of manufacturing mechanical equipment in mechanical engineering. Method. It represents the analysis of scientific and technical information on "digitalization" in the development and issues of development of end-to-end technologies for the manufacture of mechanical equipment in mechanical engineering and the synthesis of tasks and development. The results. It is shown that the generally accepted technology for the production of metal parts and, accordingly, units of aggregates and machines in mechanical engineering consists of the main sequential technological operations: cutting of rolled blanks; forging or stamping of finished parts or forgings and stampings for subsequent mechanical processing by cutting; casting of finished parts or cast blanks for processing; processing of forgings or stampings and castings by cutting; if necessary, heat treatment of parts; if necessary, covering of parts; - assembly of nodes and machines. The given examples for each component technology showed a wide range of numerical software control products.A model of components in the "digitalization" of mechanical equipment manufacturing technologies and a model of the main components of the end-to-end technology of manufacturing metal engineering parts and "digitalization" elements have been developed.The relevance of developments on smoothing the joints of lines describing the shapes of product details is substantiated. It is proposed to use the possibilities of Bezier lines more widely. Scientific novelty. The elements of scientific novelty are in the created model of "digitization" of the components of end-to-end technologies for the manufacture of mechanical equipment in mechanical engineering and in the formulation of the application of Bezier lines for smoothing the joints of tool movement lines in the development of technological processes. Practical significance. The results of the article can be used in the development of end-to-end technologies for manufacturing mechanical equipment in mechanical engineering.

Curious case of a spurious medical gas cylinder.

INTRODUCTION Anaesthesia machines are supplied through a central medical gas pipeline system (MGPS) or cylinders. Type E cylinders are used as backup when the pipeline system fails.[1,2] Ensuring a filled type E oxygen cylinder attached to the anaesthesia machine is an element of the pre-use daily equipment checklist in the operating rooms (ORs).[3] Various safety features ensure that correct gas is delivered to the patient through the cylinders, namely colour coding and label, pin index system, etc. Pin index is unique to each gas and prevents connection of wrong cylinder to the anaesthesia machine.[4] We report our recent encounter with a cylinder, colour coded (black body and white shoulder) and labelled for oxygen but with a pin index and label on valve for nitrous oxide (N2O). CASE REPORT In an OR, the backup oxygen cylinder was empty. Hence, another oxygen cylinder (as identified by ‘O2’ marking and colour coding) was attempted to attach to the hanger yoke assembly. However, it could not be attached. Upon close inspection of the cylinder, the holes on the cylinder corresponded to pin index of N2O, (3,5) and N2O was engraved on the valve [Figure 1a and b]. This cylinder could be successfully attached to the nitrous oxide hanger yoke assembly without any leak [Figure 1c]. Also, there was doubt regarding the actual contents of the cylinder. The anaesthetic gas monitor (AGM) of the anaesthesia workstation (Datex Ohmeda 9100c NXT, GE Healthcare, United Kingdom) was utilized after disconnecting the N2O and air pipelines. The oxygen pipeline was not disconnected since N2O cannot be turned on without oxygen. A test lung was connected to the breathing circuit, and gas flow was turned on (O2:N2O 50:50; 5 L/min each). The N2O flowmeter was supplied by the spurious cylinder and oxygen flowmeter by the pipeline. As depicted by the AGM, both the inspiratory and expiratory gases had just oxygen and no N2O, indicating that the actual content of the cylinder in question was oxygen. The faulty oxygen cylinder was labelled appropriately for caution and segregated, and another oxygen cylinder was attached as backup for the day. The event was reported to the hospital authorities for suitable action towards the supplier/manufacturer.Figure 1: (a) Cylinder, colour coded for oxygen (black body and white shoulders) with N2O engraved over the valve (black arrow); (b) Pin holes corresponding to pin index of nitrous oxide (white arrow); and (c) The spurious cylinder attached to nitrous oxide hanger yoke, since it could not be attached to the oxygen hanger yokeDISCUSSION Despite the technical advances and incorporation of safety features, potentially catastrophic events continue to happen every now and then. Pauling and Ball reviewed case reports pertaining to the delivery of anoxic gas mixtures to the patients, both prior to and after the obligatory safety checklist.[5] The safety features are prone to disregard which may arise out of unawareness, disinterest or accident. This can occur at any point in the process, manufacturer, supplier or end user. Pin index system has been instrumental in preventing erroneous connection of cylinder. The pin index system is also used to fill the correct gas in the cylinder.[6] However, this system is not infallible. It can be bypassed by using an adapter while filling the gas or using multiple washers (Bodok seal) while attaching to the hanger yoke assembly of anaesthesia machine. The same seemed to have happened in our case as well, where oxygen was filled in the cylinder through a N2O valve. Had it been the other way around with N2O filled in an oxygen cylinder, the outcome could have been catastrophic. Ours was a clear instance of threading a N2O valve onto a shoulder and body which was colour coded and labelled for oxygen. This could have been the result of amateurish work in an unsupervised environment at the point of manufacturing. Sensitization, upskilling, training and reeducating at this level of the supply chain are mandatory to avoid such mishaps. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Cryo-EM structure of the RADAR supramolecular anti-phage defense complex.

RADAR is a two-protein bacterial defense system that was reported to defend against phage by "editing" messenger RNA. Here, we determine cryo-EM structures of the RADAR defense complex, revealing RdrA as a heptameric, two-layered AAA+ ATPase and RdrB as a dodecameric, hollow complex with twelve surface-exposed deaminase active sites. RdrA and RdrB join to form a giant assembly up to 10 MDa, with RdrA docked as a funnel over the RdrB active site. Surprisingly, our structures reveal an RdrB active site that targets mononucleotides. We show that RdrB catalyzes ATP-to-ITP conversion invitro and induces the massive accumulation of inosine mononucleotides during phage infection invivo, limiting phage replication. Our results define ATP mononucleotide deamination as a determinant of RADAR immunity and reveal supramolecular assembly of a nucleotide-modifying machine as a mechanism of anti-phage defense.

Study on the analysis of cotton ginning machine transmission system

India is the second ranked large cotton producing country of world. Separation of fibre and seed is initial process desired for converting cotton crop to any finished product. Mostly ginning machines are developed as per need and volume of work to be processed. Ginning machine is main processing tool between cotton producers and textile industries. Commonly machines using double roller are utilized in India. As per the need from time to time Indian farmers adopted tools and techniques to provide high-quality cotton to local and overseas textile mills, ginning machines are upgraded step by step to cope up the demands. Twin roller ginning machine needs to be further developed and enhanced so as to improve performance of textile industries. In this paper, the analysis is conducted for betterment of current design. Double roller gin is focused here using analytical analysis for force acting on gears while transmission of torque, as well as balancing of components and thrust force acting on the bearing that creates vibration in the complete ginning machine assembly. Innovative design aspects considered in this work are found to be very effective for improve of double rolling gin machine performance.

Comprehensive classification of proteins based on structures that engage lipids by COMPOSEL

Structures can now be predicted for any protein using programs like AlphaFold and Rosetta, which rely on a foundation of experimentally determined structures of architecturally diverse proteins. The accuracy of such artificial intelligence and machine learning (AI/ML) approaches benefits from the specification of restraints which assist in navigating the universe of folds to converge on models most representative of a given protein's physiological structure. This is especially pertinent for membrane proteins, with structures and functions that depend on their presence in lipid bilayers. Structures of proteins in their membrane environments could conceivably be predicted from AI/ML approaches with user-specificized parameters that describe each element of the architecture of a membrane protein accompanied by its lipid environment. We propose the Classification Of Membrane Proteins based On Structures Engaging Lipids (COMPOSEL), which builds on existing nomenclature types for monotopic, bitopic, polytopic and peripheral membrane proteins as well as lipids. Functional and regulatory elements are also defined in the scripts, as shown with membrane fusing synaptotagmins, multidomain PDZD8 and Protrudin proteins that recognize phosphoinositide (PI) lipids, the intrinsically disordered MARCKS protein, caveolins, the β barrel assembly machine (BAM), an adhesion G-protein coupled receptor (aGPCR) and two lipid modifying enzymes - diacylglycerol kinase DGKε and fatty aldehyde dehydrogenase FALDH. This demonstrates how COMPOSEL communicates lipid interactivity as well as signaling mechanisms and binding of metabolites, drug molecules, polypeptides or nucleic acids to describe the operations of any protein. Moreover COMPOSEL can be scaled to express how genomes encode membrane structures and how our organs are infiltrated by pathogens such as SARS-CoV-2.

A scale-spanning integrative modeling strategy to study structure, dynamics, and function of vital molecular machines.

Life is motion driven through cellular processes carried out by molecular machines. To understand and manipulate such cellular processes, scale-spanning knowledge of structure, dynamics, and function of molecular machines is needed. This knowledge cannot be obtained by one method alone. Therefore, I developed a strategy that combines ab initio structure prediction, molecular dynamics (MD) simulation, and quantum chemical calculations with data from structure resolving experiments to investigate the assembly and functional cycle of molecular machines from the electron up to the molecular level. First, experimental data is converted into static structural models of different mechanistic states of molecular machines using bioinformatics methods. Second, active sites are refined at sub-Å resolution and intermediate states inaccessible by experiments are identified employing QM/MM simulations. Third, the obtained refined snapshots are merged to map the dynamics of the processes in their native environment using MD simulations. The strategy provides insights into the interplay between local processes like chemical reactions at the active sites and global conformational changes driving cellular function. These insights lead to mechanistic hypotheses and key functional residues that motivate targeted experiments, like mutagenesis studies, to validate the structural dynamic models. This generally applicable strategy was applied e.g. to obtain insights into ATP‑hydrolysis driven protein recycling by the proteasome [Schweitzer et al. (2016) PNAS; Hung et al. (2022) Nature Communications] or the assembly of proteins involved in photosynthesis like photosystem II [Zabret et al. (2021) Nature Plants] or vesicle inducing protein in plastids Vipp1 [Gupta et al. (2021) Cell].

Problems of forecasting the length of the assembly cycle of complex products realized in the MTO (make-to-order) model

This article presents the problem of forecasting the length of machine assembly cycles in make-to-order production (Make-to-Order). The model of Make-to-Order production and the technological process of manufacturing the finished product are presented. The possibility of developing a novel method, using artificial intelligence solutions, to estimate machine assembly times based on historical company data on manufacturing times for structurally similar components, is described. It is assumed that the result of the developed method will be an intelligent system supporting efficient and accurate estimation of machine assembly time, ready for implementation in production conditions. Such data as part availability, human resource availability and novelty factor will be used as input data for learning the neural network, while the output variable during learning the neural network will be the actual machine assembly time.

Establishment of Mathematical Model of Different Burr Removal Methods for Automobile Valve Body Parts

In the process of auto body parts processing, machining surface at the junction will produce burrs or flares. The existence of burr will have a bad effect on the machining accuracy, assembly accuracy and appearance quality of parts. In industrial production, the cost of removing these burrs is enormous. In automotive parts, the cost of deburring body parts can account for machining costs15% - 20%. Industry practice has shown that the actual cost of deburring systems increases as the complexity and accuracy of parts increase. Precision parts such as automobile valve body require high precision, and burr is usually removed by grinding. In grinding process, different types of burr will adopt different grinding process to purify, frequent adjustment process will affect the production efficiency, so the combination with the characteristics of grinding, the grinding grain edge radius, equivalent negative rake Angle and other factors into consideration, burr types can be divided into three categories, respectively on the three types of burr mathematical modeling, The removal mechanism of different kinds of burr is explained theoretically, which lays a theoretical foundation for improving efficiency in production practice.

Selected case studies regarding research-based education in the area of machine and civil assemblies

The paper presents selected case studies in the area of research and teaching activities focused on technical assemblies. The aim of the work is to discuss the current trends in assembly-related research activities in partner universities of the EDURES project and to present teaching methodology related to the research. Due to the great importance of research-based education for innovative teaching methodology, research utilization into teaching process is addressed in the paper as a priority of modern teaching, which uses digital platforms and is focused on fast dissemination of the research results among both researchers and higher education students.

Experimental investigation of a multilayer nitride coating deposited on austenitic coating steel

Friction is the drawback in automotive and industrial machining parts and assembly. To overcome the wear loss due to friction the surface property must be enhanced using suitable technology. Arc deposition is a PVD type of coating which improves the property such as hardness, roughness, corrosion, and tribological on a server work environment. Titanium nitride (TiN) and titanium aluminum nitride (TiAlN) are hard ceramic coating materials. The mechanical and wear properties of stainless steel (SS304) coated with Method of cathodic arc deposition (CAD) The ability to slide against Ti–6Al–4 V alloy has improved significantly. The three coated samples' surface hardness, roughness, and wear rate are measured and compared. The applied tension (2–6 N), sliding velocity (0.32–0.75 m/s), and sliding distance (580–1500 m) tribological parameters are modified during the wear test with the ball-on-disc. In comparison to other types of coatings, On the SS316L surface, the TiN coating provides exceptional mechanical and tribological properties.

Development prospect of heat supply and peak shaving of nuclear power units in Shandong power grid

Under the current national “dual carbon” economic development goal, nuclear energy, as a clean, low-carbon, safe and efficient form of energy, has the advantage of natural heat. Central heating is an important area that consumes coal and generates carbon emissions. Therefore, the development of nuclear heating is conducive to improving the energy utilization structure and upgrading the industry. Based on the current situation of the nuclear motor assembly machine in Shandong Province and the power supply composition structure of the provincial power grid, this paper has carried out the relevant technical analysis and prospects for the peak shaving of nuclear heating.

Results of dynamic analysis of double-inlet screw conveyor machine assembly

The article presents the results of theoretical studies of vertical and deflecting vibrations of two-stroke screws with a wavy surface and conveyor screws with a curved base and an elastic element. Based on the analysis of the obtained graphs of the relations of laws and motion parameters, their optimal values are justified. Here, the options for applying rubber gaskets to bearing bearings are considered in two versions, that is, with the same and two different types of stencils. When the rubber bushings of the bearing supports are taken in two different elasticities, the change laws of the vibration of the screw are obtained depending on the size of the supports, the moment of inertia of the screw and the change of the technological resistance force. Introduction

Improving machine assemblies’ diagnosis with the use of thermal imaging camera

Thermal imaging camera is used in the construction industry, energy industry and some other areas. Considering that a vehicle uses engines, interacting parts, electrical wiring and electrical equipment, it is advisable to use thermal imaging diagnostic method for vehicles as well, including specialized (trucks, road construction and others). Thermal imaging method of machinery diagnosing can be used in the conditions of the specialized automobile service enterprise (dealer or universal), visiting service (servicing of specialized machines by dealer), as well as using own service base of the enterprise. This task is especially urgent in connection with the necessity of pre-shift inspection, which is usually carried out by the company's own maintenance service. Rapid vehicle diagnosis using instrumented testing is therefore an important task. Brakes, bearings, engine, gearbox, transfer case, axles and electrical wiring can all be checked with a thermal imaging camera. Possibility of application of a thermal imaging camera for determining the condition of an angle or an aggregate both by comparison (brake mechanisms, hub bearings) and by determining the actual temperatures of the diagnosed object and comparing them with the approximate values which are determined beforehand on the basis of the previously made measurements. Thus, the use of thermal imaging method of vehicle diagnostics will allow for faster and more accurate assessment of the actual condition of vehicle units and assemblies, increasing its efficiency.

A single 2′-O-methylation of ribosomal RNA gates assembly of a functional ribosome

RNA modifications are widespread in biology and abundant in ribosomal RNA. However, the importance of these modifications is not well understood. We show that methylation of a single nucleotide, in the catalytic center of the large subunit, gates ribosome assembly. Massively parallel mutational scanning of the essential nuclear GTPase Nog2 identified important interactions with rRNA, particularly with the 2′-O-methylated A-site base Gm2922. We found that methylation of G2922 is needed for assembly and efficient nuclear export of the large subunit. Critically, we identified single amino acid changes in Nog2 that completely bypass dependence on G2922 methylation and used cryoelectron microscopy to directly visualize how methylation flips Gm2922 into the active site channel of Nog2. This work demonstrates that a single RNA modification is a critical checkpoint in ribosome biogenesis, suggesting that such modifications can play an important role in regulation and assembly of macromolecular machines.

Synthesis and Structure-Activity Studies of β-Barrel Assembly Machine Complex Inhibitor MRL-494.

In the hunt for new antibiotics with activity against Gram-negative pathogens, the outer membrane β-barrel assembly machine (BAM) complex has become an increasingly interesting target. The recently reported BAM complex inhibitor, MRL-494, was discovered via a screening campaign for molecules that target the outer membrane. Notably, MRL-494 was reported to be an unintended byproduct generated during the synthesis of an unrelated compound, and as such no synthesis of the compound was disclosed. We here present a convenient and reliable route for the synthesis of MRL-494 that scales well. The antibacterial activity measured for synthesized MRL-494 matches that reported in the literature. Furthermore, MRL-494 was found to exhibit potent synergistic activity with rifampicin against Gram-negative bacteria, including E. coli, K. pneumoniae, A. baumannii, and P. aeruginosa. MRL-494 was also found to cause outer membrane disruption and induction of the Rcs stress response pathway. In addition, we undertook a focused structure-activity study specifically aimed at elucidating the roles played by the two guanidine moieties contained within the structure of MRL-494.

Distributed Energy-Efficient Assembly Scheduling Problem with Transportation Capacity

The real-life assembly production often has transportation between fabrication and assembly, and the capacity of transportation machine is often considered; however, the previous works are mainly about two-stage distributed assembly scheduling problems. In this study, a distributed energy-efficient assembly scheduling problem (DEASP) with transportation capacity is investigated, in which dedicated parallel machines with symmetry under the given conditions, transportation machines and an assembly machine are used. An adaptive imperialist competitive algorithm (AICA) is proposed to minimize makespan and total energy consumption. A heuristic and an energy-saving rule are used to produce initial solutions. An adaptive assimilation with adaptive global search and an adaptive revolution are implemented, in which neighborhood structures are chosen dynamically, and revolution probability and search times are decided by using the solution quality. The features of the problem are also used effectively. Computational experiments are conducted on a number of instances. The computational results demonstrate that the new strategies of AICA are effective and efficient and AICA can provide promising results for the considered DEASP.