Single Part Research Articles

Exploitation of transition temperatures of NiTi- SMA by adjusting SLM parameters

Abstract It is well known that the transition temperatures, e.g. the austenite peak temperature Ap, of NiTi Shape Memory Alloys (SMAs) can be adjusted by changing the alloy composition. This topic recently became more interesting due to the possibilities to produce SMA-parts by additive manufacturing, specifically by Selective Laser Melting (SLM). The potential of new designs and smart structures by so-called 4D-printing with locally adjusted transition temperatures Ap potentially opens up new applications and novel temperature-responsive medical devices. This work focuses on the SLM manufacturing parameters exposure time ET (scanning speed) and laser power P and their impact on the transition temperature Ap beyond the commonly used generic process parameter energy density ED. By systematical variation of process- and scan-parameters, the impact of the P, ET, sample orientation and layer height LH as well as interdependencies between them have been studied. A wide range of transition temperatures Ap between -20°C and 70°C has been reached from one starting material by varying ET. These findings potentially allow the manufacturing of smart devices with multi-stage deformation processes in a single 4Dprinted part.

Study of additive manufacturing techniques to obtain tactile graphics

Tactile graphics (TG) are intended to facilitate communication for people with total or partial visual impairment. For this purpose, TG include elements in relief that can be perceived through the sense of touch. TG can be fixed or portable. Fixed TG are expensive, as they are typically produced in very short runs, mostly single part production. Portable TG can be made by thermoforming polymer sheets, but a mould is still required, even though production runs are short (some tens). For this reason, the use of Rapid Manufacturing (RM) and Rapid Tooling (RT) strategies to manufacture TG can be of great interest. In this work, a literature review to study the application of Additive Manufacturing (AM) to obtain TG, both as RM and RT, is carried out. The review reveals the suitability of AM techniques to manufacture TG. In addition, some AM techniques are analysed to be used for a new type of TG, which is based on the deposition of glaze on ceramic tiles.

Optical inline monitoring of the burnish surface in the punching process

Punching is a wide-spread production process, applied when massive amounts of the ever-same cheap parts are needed. The punching process is sensitive to a multitude of parameters. Unfortunately, the precise dependencies are often unknown. A prerequisite for optimal, reproducible and transparent process alignment is the knowledge of how exactly parameters influence the quality of a punching part, which in turn requires a quantitative description of the quality of a part. We developed an optical inline monitoring system, which consists of a combined imaging and triangulation sensor as well as subsequent image processing. We show that it is possible to capture images of the cutting surface for every part within production. We automatically derive quality parameters using the example of the burnish height from 2D images. In addition, the 3D parameters are calculated and verified from the triangulation images. As an application, we show that the status of tool wear can be inferred by monitoring the burnish height, with immediate consequences for predictive maintenance. Although limited by slow images processing in our prototype, we conclude that connecting machine and process parameters with quality metrics in real time for every single part enables data-driven process modelling and ultimately the implementation of intelligent punching machines.

Dry Powder Inhalers in the Digitalization Era: Current Status and Future Perspectives.

During the last decades, the term “drug delivery systems” (DDSs) has almost fully replaced previously used terms, such as “dosage forms”, in an attempt to emphasize the importance of the drug carrier in ensuring the claimed safety and effectiveness of the product. However, particularly in the case of delivery devices, the term “system”, which by definition implies a profound knowledge of each single part and their interactions, is not always fully justified when using the DDS term. Within this context, dry powder inhalers (DPIs), as systems to deliver drugs via inhalation to the lungs, require a deep understanding of the complex formulation–device–patient interplay. As of now and despite the progress made in particle engineering and devices design, DPIs’ clinical performance is limited by variable patients’ breathing patterns. To circumvent this pitfall, next-generation DPIs should ideally adapt to the different respiratory capacity of individuals across age, health conditions, and other related factors. In this context, the recent wave of digitalization in the health care and industrial sectors may drive DPI technology towards addressing a personalized device–formulation–patient liaison. In this review, evolving technologies are explored and analyzed to outline the progress made as well as the gaps to fill to align novel DPIs technologies with the systems theory approach.

Action-based organization of a cerebellar module specialized for predictive control of multiple body parts

The role of the cerebellum in predictive motor control and coordination has been thoroughly studied during movements of a single body part. In the real world, however, actions are often more complex. Here, we show that a small area in the rostral anterior interpositus nucleus (rAIN) of the mouse cerebellum is responsible for generating a predictive motor synergy that serves to protect the eye by precisely coordinating muscles of the eyelid, neck, and forelimb. Within the rAIN region, we discovered a new functional category of neurons with unique properties specialized for control of motor synergies. These neurons integrated inhibitory cutaneous inputs from multiple parts of the body, and their activity was correlated with the vigor of the defensive motor synergy on a trial-by-trial basis. We propose that some regions of the cerebellum are organized in poly-somatotopic"action maps" to reduce dimensionality and simplify motor control during ethologically relevant behaviors.

Ethnobotanical survey of anti-malarial plants used in Ilorin metropolis, Nigeria

An ethnobotanical survey of medicinal plants used in the treatment of malaria in Ilorin, Kwara State, Nigeria was carried out between March and June, 2019. Ethno-botanical data were collected by oral interview with the aid of a semi-structured questionnaire administered to forty-seven (47) herb sellers. The respondents were aware of the signs and symptoms of malaria and could readily distinguish the ailments from other feverish symptoms and conditions. Symptoms reported include body weakness, high body temperature (hot skin), loss of appetite, coldness, mouth bitterness, headache, coloured eyes (yellow), sleepless night and urine colouration (yellowish). From the study, a total of thirteen (13) plant species belonging to nine (9) families including Aannonaceae, Aapocynaceae, Rrubiaceae, Oochnaaceae were described as being used for the treatment of malaria. The plant parts used were leaves, root, stem bark and seed with roots being the most used plant part. It was also observed that recipes were made from combination of different parts from more than one plant species including bark, root and leaves while some were made from single plant part. The most preferred mode of administration was oral, while decoction and infusion were the most preferred method of preparation. However, the study observed that Picralima nitida, Enanchia chloranta and Morinda nucida were the frequently mentioned plants. Hence, these plant species could be considered as promising candidates for further scientific validation in the search for new, effective and affordable antimalarial drugs.

Design for Additive Manufacturing and for Machining in the Automotive Field

High cost, unpredictable defects and out-of-tolerance rejections in final parts are preventing the complete deployment of Laser-based Powder Bed Fusion (LPBF) on an industrial scale. Repeatability, speed and right-first-time manufacturing require synergistic design approaches. In addition, post-build finishing operations of LPBF parts are the object of increasing attention to avoid the risk of bottlenecks in the machining step. An aluminum component for automotive application was redesigned through topology optimization and Design for Additive Manufacturing. Simulation of the build process allowed to choose the orientation and the support location for potential lowest deformation and residual stresses. Design for Finishing was adopted in order to facilitate the machining operations after additive construction. The optical dimensional check proved a good correspondence with the tolerances predicted by process simulation and confirmed part acceptability. A cost and time comparison versus CNC alone attested to the convenience of LPBF unless single parts had to be produced.

Development of Fused Filament Fabrication desktop 3D printer enclosure using axiomatic design principles

Additive manufacturing through Fused Filament Fabrication is one of the most spread methods for obtaining functional prototypes and components, mainly for single parts demands or small manufacturing lots. This direction of use presumes the use of engineering polymers in the manufacturing process, materials that require precise control of the environment regarding printing temperature and moisture. A Do-It-Yourself enclosure mock-up for engineering polymers processing was obtained using the Axiomatic Design principles. The enclosure is compatible with low-cost Fused Filament Fabrication desktop 3D printers and satisfies the functional requirements regarding manufacturing and secure usage of engineering-grade polymers. In addition, the presented design solved the requirements regarding surveillance and remote control during the manufacturing process.

Design and Experimental Validation of a Process Chain for Thin Components Manufacturing by Micro Injection Molding Process

Abstract Micro-applications, especially in biomedical and optical sectors, require the fabrication of thin polymeric parts which can be commonly realized by micro-injection molding process. However, this process is characterized by a relevant constraint regarding the tooling. Indeed, the design and manufacturing of molds could be a very time-consuming step and so, a significant limitation for the rapid development of new products. Moreover, if the design displays challenging microfeatures, their realization could involve the use of more than one mold for the fabrication of a single thin part. Therefore, proper integration of different manufacturing microtechnologies may represent an advantageous method to realize such polymeric thin microfeatures. In this work, a micromanufacturing process chain including stereolithography, micromilling, and micro-injection molding is reported. The mold for the micro-injection molding process was fabricated by means of stereolithography and micromilling, which allowed us to produce low-cost reconfigurable modular mold, composed of insert support and a removable insert. The assessment of the proposed process chain was carried out by evaluating the dimensions and the surface finishing and texturing of the milled mold cavities and molded components. Finally, a brief economic analysis compares three process chains for fabricating the micromold showing that the proposed one reduces the manufacturing cost by almost 61% with the same production time.

Real-Time Image-Based Feedback Control of Laser Powder Bed Fusion

Abstract This letter presents the design and experimental validation of a real-time image-based feedback control system for metal laser powder bed fusion (LPBF). A coaxial melt pool video stream is used to control laser power in real-time at 2 kHz. Modeling of the melt pool image response to changes in the input laser power is presented. Based on this identified model, a real-time feedback controller is implemented experimentally on a single track and part scales. On a single-track scale, the controller successfully tracks a time-varying melt pool reference. On a part-level scale, the controller successfully regulates the melt pool image signature to the desired reference value, reducing layer-to-layer signal variation and eliminating within-layer signal drift.

Single part reconfigurable flow line design using fuzzy best worst method

Single part reconfigurable flow line design using fuzzy best worst method

The Heraldic Shield and the Woman’s Body in the Blasons Anatomiques du corps féminin (1543)

Abstract In the French Renaissance, the term ‘anatomical blason’ (blason anatomique) designated a highly descriptive love poem praising a single part of a woman’s body, while in heraldry, the noun ‘blason’ defined the ensemble of ornamental components constituting the shield. Just as the French verb blasonner meant to describe and to interpret the shield’s material and symbolic parts, so could this verb be used in amatory poetry to signify the act of lauding the details of the beloved’s anatomical parts. This study examines the structural analogies between heraldic shield and the anatomical blason, addressing how the technical terms defining the shield’s components such as partitions, points, charges, tinctures, and the achievement could be given analogous expressions in the anatomical love poetry.

Copy neutral absence of heterozygosity on chromosome 15 distal long arm: A surrogate marker for Prader\u2013Willi/Angelman syndromes?

BackgroundCopy-neutral absence of heterozygosity (CN-AOH) observed on a single chromosome or part of a chromosome may be indicative of uniparental disomy (UPD) and may require additional testing when such chromosomes or chromosome regions are known to harbor imprinted genes.Case presentationHere we report 2 cases of neonates that presented to clinic with hypotonia, poor oral skills including inability to feed by mouth, weak cry, no response to noxious stimulation and vertical plantar creases (case 1) and hypotonia and respiratory distress (case 2). A preliminary chromosome analysis showed normal karyotypes in both cases while the high-resolution single nucleotide polymorphism (SNP) microarray showed copy neutral absence of heterozygosity involving chromosome 15 distal long arm. In case 1, the CN-AOH involved a 28.7 Mb block from genomic coordinates 73703619_102429049. In case 2, the CN-AOH involved a 15.3 Mb block from genomic coordinates 54729197_70057534. In both cases, methylation-specific PCR did not detect an unmethylated allele for the SNRPN gene suggesting either a deletion of paternal allele or maternal UPD for chromosome 15. Since microarray analysis did not show any copy number alterations on chromosome 15, a microdeletion was ruled out.ConclusionsBased on our cases, we suggest that CN-AOH on chromosome 15, even if it does not involve the critical region of 15q12q13, should warrant additional studies for diagnosis of Prader–Willi/Angelman syndromes.

Bonding strength calculation in multicomponent plastic processing technologies

ABSTRACT This study focuses on overmolding, a unique injection molding process. It enables a seamless combination of multiple materials into a single part. The bottleneck of overmolding is the interface strength between the paired elements. Interface strength depends on numerous factors, such as the interface topology, the physical and chemical properties of the paired materials, and the processing parameters of overmolding. These factors have a large number of possible combinations. This necessitates a modeling approach to predict the interface properties and find the optimal processing parameters of overmolding at an early design stage. Although injection molding is a well-known field for simulation, adhesion modeling between the substrate and overmolded elements is missing in all available simulation software. Our goal is to develop a simulation methodology that combines analytical models with simulation tools, to predict interface strength during overmolding. The principal novelty of the proposed methodology is that it considers the space-time dependency of the interface temperature – this has a significant influence on interface strength. We proved that the methodology we developed gives the most accurate results; it predicts the bonding strength of overmolded ABS, PC and PS parts with an error of less than 7%.

Probabilistic decision support system using machine learning techniques : A case study of Cardiovascular diseases

Diseases are an irregular event that affects single or multiple body parts of a human being. Different kinds of diseases are growing day by day in terms of lifestyle and heritage. Among all the ones, it turns out that heart disease is the most prevalent disease, and the consequence of this disease is dangerous relative to all other situations. In this paper, initially the author calculates immanent discreteness between two probability separations, based on information theory or relative entropy using Kullback-Leibler divergence (KL divergence). It can be used as shortcuts in the calculation of other widely used methods, such as mutual information for feature selection before modeling, and cross-entropy used as a loss function for many different classifier models. Seven computational intelligence techniques named logistic regression (LR), support vector machine (SVM), naïve bayes (NB), random forest (RF), and k-nearest neighbor (K-NN) have been applied and a comparative study had been drawn. The heart disease dataset is taken from the Department of Cardiology, Excelcare Hospitals, Guwahati, Assam and the analysis of performance in each technique has been evaluated.

Joermungandr bolti, an exceptionally preserved 'microsaur' from the Mazon Creek Lagerstätte reveals patterns of integumentary evolution in Recumbirostra.

The Carboniferous Pennsylvanian-aged (309–307 Ma) Mazon Creek Lagerstätte produces some of the earliest fossils of major Palaeozoic tetrapod lineages. Recently, several new tetrapod specimens collected from Mazon Creek have come to light, including the earliest fossorially adapted recumbirostrans. Here, we describe a new long-bodied recumbirostran, Joermungandr bolti gen. et sp. nov., known from a single part and counterpart concretion bearing a virtually complete skeleton. Uniquely, Joermungandr preserves a full suite of dorsal, flank and ventral dermal scales, together with a series of thinned and reduced gastralia. Investigation of these scales using scanning electron microscopy reveals ultrastructural ridge and pit morphologies, revealing complexities comparable to the scale ultrastructure of extant snakes and fossorial reptiles, which have scales modified for body-based propulsion and shedding substrate. Our new taxon also represents an important early record of an elongate recumbirostran bauplan, wherein several features linked to fossoriality, including a characteristic recumbent snout, are present. We used parsimony phylogenetic methods to conduct phylogenetic analysis using the most recent recumbirostran-focused matrix. The analysis recovers Joermungandr within Recumbirostra with likely affinities to the sister clades Molgophidae and Brachystelechidae. Finally, we review integumentary patterns in Recumbirostra, noting reductions and losses of gastralia and osteoderms associated with body elongation and, thus, probably also associated with increased fossoriality.

DFC

Knowledge discovery data (KDD) is a research theme evolving to exploit a large data set collected every day from various fields of computing applications. The underlying idea is to extract hidden knowledge from a data set. It includes several tasks that form a process, such as data mining. Classification and clustering are data mining techniques. Several approaches were proposed in classification such as induction of decision trees, Bayes net, support vector machine, and formal concept analysis (FCA). The choice of FCA could be explained by its ability to extract hidden knowledge. Recently, researchers have been interested in the ensemble methods (sequential/parallel) to combine a set of classifiers. The combination of classifiers is made by a vote technique. There has been little focus on FCA in the context of ensemble learning. This paper presents a new approach to building a single part of the lattice with best possible concepts. This approach is based on parallel ensemble learning. It improves the state-of-the-art methods based on FCA since it handles more voluminous data.

Controllable construction and theoretical simulation of silica aerogel/polymer composites with electrostatic interaction interfaces

In our previous work, aerogel/polymer composites with electrostatic interaction interface were successfully constructed. Interesting experimental phenomena in heat and stress transfer had also been found. On the basis of these works, we had been thinking about how to control the characteristics of electrostatic interaction phase interface, and how these phase interface characteristics affected the properties of materials. In this paper, the electrostatic interaction phase interface characteristics of the composite were regulated from the aspects of polymer chain movement, charge amount and charge distribution. The effects of phase interface characteristics on stress and heat transfer behavior of the composites were analyzed from the aspects of experimental test characterizations and molecular dynamics simulation. The results showed that the action region of electrostatic attraction phase interface can be controlled by the properties of polymer side chain and charged monomer. The density, heat transfer characteristics and stress transfer behavior of the composites were affected. α-Methyl was beneficial to the thermal stability of the composites, and the thermal conductivity was about 0.012 W m−1K−1. When the alkyl side chain was long, the molecular chain arrangement was irregular, the reorientation ability of the molecular chain was poor, and the molecular chain breaks in the compression stage. In the theoretical simulation, it can be found that more charged groups in a single charged part of the molecule led to the increase of cationic density in the organic phase, which made it easier to form effective chemical bonds in the crosslinking process, and the final crosslinking degree was improved.

Design of a Wireless Single Arm Electrocardiograph System

Electrocardiograms (ECGs) are a method of assessment of cardiac electrical activity. It is the heart’s electrophysiological activity which occurs by the conduction of electrical impulses from the Sinoatrial (SA) node and the Atrioventricular (AV) node across the cardiac muscles and is displayed as a voltage-time graph. Conventionally, they have been acquired using a system of ten surface electrodes placed in different locations throughout the body in a 12-lead system. Single Arm ECG systems, where the ECG rhythm is obtained from only a single part of the body, replace the need for ten different electrodes to detect the heart's activity. Three pre-gelled electrodes are applied in different locations of the left arm to derive the sinus rhythm signal of a subject. An op-amp based hardware instrument has been developed for this purpose with active filters and amplifiers to perform signal conditioning. This paper demonstrates the implementation of a single arm hardware system of small size to improve portability, used as an ECG detection method and the results from various subjects taken at different gain values to improve the view of the signal, while also presenting a method to transmit the data of the signals wirelessly through an Internet-of-things (IoT) platform.

Monomer model: an integrated characterization method of geometrical deviations for assembly accuracy analysis

PurposeAssembly accuracy is the guarantee of mechanical product performance, and the characterization of the part with geometrical deviations is the basis of assembly accuracy analysis.Design/methodology/approachThe existed small displacement torsors (SDT) model cannot fully describe the part with multiple mating surfaces, which increases the difficulty of accuracy analysis. This paper proposed an integrated characterization method for accuracy analysis. By analyzing the internal coupling relationship of the different geometrical deviations in a single part, the Monomer Model was established.FindingsThe effectiveness of the Monomer Model is verified through an analysis of a simulated rotor assembly analysis, and the corresponding accuracy analysis method based on the model reasonably predicts the assembly deviation of the rotor.Originality/valueThe Monomer Model realizes the reverse calculation of assembly deformation for the first time, which can be used to identify the weak links that affect the assembly accuracy, thus support the accuracy improvement in the re-assembly stage.