Manufacturing Tools Research Articles

Evaluation of tone annoyance metrics on reverberation room measurements of HVAC equipment

Reverberation rooms are a primary tool for HVAC equipment manufacturers to calculate equipment sound power levels, which lead directly to equipment sound ratings. While sound quality has been included in standards, namely, the withdrawn AHRI 1140, the adoption and value of those standards has been minimal leaving specifiers to construct their own tone quality metrics. This paper will evaluate the application of common sound quality metrics, specifically tonal metrics, to reverberation room measurements. Room response is a critical factor in measuring tone prominence, especially at lower frequencies where adjacent frequency tones can vary by 6dB or more. Metrics evaluated include TTNR, Prominence, Tonality and a new metric developed in ASHRAE 1707-TRP.

Jeans and their Fashionable Meanings: Revisiting Beverly Gordon's Cultural Conceptual Framework

Jeans and their Fashionable Meanings: Revisiting Beverly Gordon's Cultural Conceptual Framework

Objectivization of the occlusion effect induced by earplugs in laboratory conditions—Effect of earplug type, insertion depth and background noise levels

Blocking the earcanal’s entrance with an earplug can lead users to experience discomforts, one being the occlusion effect (OE), typically described as a distorted perception of one’s own voice. This discomfort sometimes causes users to misuse or remove their earplugs which significantly lower their efficiency. Reducing the OE generated by earplugs is therefore critical to make them more comfortable. However, assessing the OE is cumbersome and time-consuming as participants’ feedback is required. Moreover, the influence of factors on the OE, namely, the type or earplug, the insertion depth, and the background noise level, remains to be understood. Hence, this ongoing research aims at objectivizing the OE induced by earplugs during speech. To do so, the OE is assessed in laboratory conditions with 30 normal hearing participants using a questionnaire and by using surrogate earplugs for in-ear microphonic measurements. Various sound pressure level-based indicators are proposed and correlated to the (dis)comfort during the objectivization step. Multiple combinations of earplugs, insertion depths and background noise levels are tested to obtain a ranking of the conditions generating more or less OE. The objectivization of the OE will be a useful tool for manufacturers developing new earplugs without requiring participants’ feedback.

Leadership of The Head of Madrasah in Carrying Out Academic Supervision To Improve Teacher Performance at MA Hidayatul Mubtadiin

The head of the madrasa plays a strategic role in improving the quality of education in madrasahs, especially the quality of educators or teachers. Teacher As a person who is at the forefront and responsible for the development and progress of students. This study aims to find out how the leadership of the head of the madrasah through academic supervision to improve teacher performance at MA Hidayatul Mubtadiin Jatiagung. In this study, qualitative research methods were used. Data collection methods are in the form of observation, interviews and documentation. Data analysis includes data collection, data provision, and drawing conclusions. The results showed that the implementation of basic supervision in improving teacher performance at Ma Hidayatul Mubtadiin Jatiagung, In planning the supervision program, the principal had done a good job of planning, but there were still shortcomings. This is known from data showing that the supervision program is planned twice a year. Program planning has been well communicated with the teacher council. In implementing the supervision program, the principal has carried out class visits in accordance with the schedule and supervision assessment sheets that have been approved by the teacher council and the principal. However, in providing guidance on the manufacture of learning tools, it is not optimal. In the follow-up supervision, the principal did not analyze the findings of the supervision. The principal also did not make any findings back as reinforcement after supervision. Thus, follow-up supervision is not optimal.

Prototype Perkakas Mekanik Berbasis Benda Kerja Praktik Mahasiswa

The learning process for vocational higher education applies a composition of 30 percent theory and 70 percent practice. A larger composition of practical learning will guarantee an increase in the quality of students' expertise, because in practical learning students practice in workshops that produce workpieces in the form of products that have economic value. Workpieces are made by manufacturing processes using industrial-based machines such as lathes, milling machines, drills, grinders, and others. Practical work in the workshop is carried out for one week or the equivalent of 38 hours. The quality of the workpiece is also a parameter for student assessment which will become one of the semester graduation requirements so as to produce quality students in their fields. However, there are problems in practicum activities in the vocational field that are most experienced by almost all vocational education institutions, namely workpiece waste. Vaccination education managers must think about how to optimize or utilize work objects resulting from student practice. Not a few students' work is ignored or thrown away and not utilized. This is the background of this research. This study aims to make mechanical device products that have economic value by utilizing students' work. The product manufacturing method begins with data collection, planning and drawing, the manufacturing process, assembling, and testing. From the results of the tool making, 4 types of prototype products were obtained, namely table vise, bending tools, C clamps, mini press tools. From the four products made, it can be concluded that the tool manufacturing process went according to plan and optimal results were obtained.

Towards Lean Manufacturing in Developing Countries: Research Gaps and Directions in Tanzania

In the current knowledge-driven economy, many industries across the globe are forced to adopt manufacturing technologies such as lean manufacturing to remain competitive in the globalized world. Despite the increase in lean manufacturing implementations, the adoption rate in Tanzania is very low and estimated to be 8 percent. Likewise, the sustainability of lean manufacturing tools and practices is still questionable, which shows the need to develop lean maturity models. To date, several lean maturity models have been developed but there is a lack of maturity models that consider different levels of manufacturing industries. The study presented in this paper focused on the pre-implementation, implementation, and post-implementation phases of lean manufacturing. To achieve this aim, a systematic literature review and social network analysis using VOS viewer 1.6.18 were conducted. The literature was obtained from four academic databases: Emerald, Elsevier, Springer, and Taylor and Francis. The search covered the period from 2010 to 2022. Of the 100 publications analyzed on lean manufacturing, only 1 percent is from low-income developing countries and 5 percent of publications from Africa. The study has identified that there are few numbers of research publications on lean manufacturing in Africa and low and lower-middle-income developing countries in general, as a result there is a low rate of implementation of lean manufacturing in low and lower-middle-income developing countries. It is recommended that more studies on the drivers and barriers, critical success factors, and lean assessment be conducted in developing countries.

Improved wear resistance of CBN tool enabled by hBN as a water-based lubricant additive through suppressing tribochemical reactions

Cubic boron nitride (CBN) tool is one of the most extensively used tools in modern industrial processing and manufacturing. The service life of CBN tools has extraordinary significance for machining efficiency and surface finish of workpieces. Here, we investigated the tribological behaviors of CBN/Si3N4 pairs to simulate the process of CBN tools cutting ceramics and demonstrated that the use of optimal 0.02 wt% non-toxic and eco-friendly hexagonal boron nitride (hBN) aqueous solution as a water-based cutting fluid enabled to reduce the wear rate of CBN by ∼64%, and improve the material removal of Si3N4 by ∼13% compared to pure water lubrication. Further analysis indicated that the physical adsorption of hBN nanosheets played a dominant role in the lubrication at the sliding interface where the direct contact of interfacial asperities was separated and then the tribochemical reactions of CBN with water were suppressed. The results help in the development of environmentally friendly lubricants to match the requirements of mechanical processing for difficult-to-machine materials.

Condition Monitoring of Additively Manufactured Injection Mould Tooling: A Review of Demands, Opportunities and Potential Strategies.

Injection moulding (IM) is an important industrial process, known to be the most used plastic formation technique. Demand for faster cycle times and higher product customisation is driving interest in additive manufacturing (AM) as a new method for mould tool manufacturing. The use of AM offers advantages such as greater design flexibility and conformal cooling of components to reduce cycle times and increase product precision. However, shortcomings of metal additive manufacturing, such as porosity and residual stresses, introduce uncertainties about the reliability and longevity of AM tooling. The injection moulding process relies on high volumes of produced parts and a minimal amount of tool failures. This paper reviews the demands for tool condition monitoring systems for AM-manufactured mould tools; although tool failures in conventionally manufactured tooling are rare, they do occur, usually due to cracking, deflection, and channel blockages. However, due to the limitations of the AM process, metal 3D-printed mould tools are susceptible to failures due to cracking, delamination and deformation. Due to their success in other fields, acoustic emission, accelerometers and ultrasound sensors offer the greatest potential in mould tool condition monitoring. Due to the noisy machine environment, sophisticated signal processing and decision-making algorithms are required to prevent false alarms or the missing of warning signals. This review outlines the state of the art in signal decomposition and both data- and model-based approaches to determination of the current state of the tool, and how these can be employed for IM tool condition monitoring. The development of such a system would help to ensure greater industrial uptake of additive manufacturing of injection mould tooling, by increasing confidence in the technology, further improving the efficiency and productivity of the sector.

Arduino Uno-based Brake Safety Design for Matic Motorcycles

Failed brakes are an event or damage to a motorized vehicle component that can cause an accident as well as be a life threat to the driver. There are several factors that can cause brake failure, including thin or worn brake pads, and clogged brake fluid hoses. The problem that often occurs is overheating in the brake system which causes brake failure (fading). Failed brake events are more common in hilly descent areas, these accidents make brake failure the second most common accident after driver negligence such as drowsiness. One of the efforts to prevent the failure of the brakes to occur is to make a brake safety system on an automatic Arduino Uno motorbike. The method applied includes planning, manufacturing, and testing of tools. This detector uses the DS18B20 sensor as input, Arduino uno as a microcontroller, 16 x 2 LCD as direct monitoring, and the output is an LED light and a buzzer. The working principle of this tool is that the temperature of the brake calipers has started to heat up, so the DS18B20 sensor works by generating data that will be displayed on the LCD, and when it reaches the temperature limit of 100 degrees Celsius at the same time the buzzer sounds and the LED light turns on and the water pump functions which will spray part of the system. braking. During the heating process, the temperature will be monitored via the LCD display on the vehicle. The test results of this tool will be affected by the hot temperature of the DS18B20 sensor.

Polymeric Heart Valves Will Displace Mechanical and Tissue Heart Valves: A New Era for the Medical Devices.

The development of a novel artificial heart valve with outstanding durability and safety has remained a challenge since the first mechanical heart valve entered the market 65 years ago. Recent progress in high-molecular compounds opened new horizons in overcoming major drawbacks of mechanical and tissue heart valves (dysfunction and failure, tissue degradation, calcification, high immunogenic potential, and high risk of thrombosis), providing new insights into the development of an ideal artificial heart valve. Polymeric heart valves can best mimic the tissue-level mechanical behavior of the native valves. This review summarizes the evolution of polymeric heart valves and the state-of-the-art approaches to their development, fabrication, and manufacturing. The review discusses the biocompatibility and durability testing of previously investigated polymeric materials and presents the most recent developments, including the first human clinical trials of LifePolymer. New promising functional polymers, nanocomposite biomaterials, and valve designs are discussed in terms of their potential application in the development of an ideal polymeric heart valve. The superiority and inferiority of nanocomposite and hybrid materials to non-modified polymers are reported. The review proposes several concepts potentially suitable to address the above-mentioned challenges arising in the R&D of polymeric heart valves from the properties, structure, and surface of polymeric materials. Additive manufacturing, nanotechnology, anisotropy control, machine learning, and advanced modeling tools have given the green light to set new directions for polymeric heart valves.

Toward a Rapid and Sustainable Recovery in the Tourism Industry Using Lean Manufacturing Principals

The tourism industry sector is among the economic growth drivers in many countries worldwide. Unfortunately, this sector was one of the most affected sectors by the COVID-19 pandemic. The objectives of this study are to implement selected lean management principles to speed up and sustain the sector’s recovery. The country of Jordan is among those countries which is depending on the tourism industry and will be selected as a model to implement the goals of this study. The number of tourists visiting Jordan on a monthly basis for two years, their nationalities, and the trip organizing agencies were collected and investigated for this study using group technology. Group technology, as a lean manufacturing tool is selected to be investigated and applied for having favorable clusters in terms of their economic, social, and health impact. Two scenarios were examined: the first scenario is clustering visitors based on their nationalities, and the second scenario is clustering based on travel agencies. Then, for each scenario, the developed tools were used to come up with recommendations for Tourism Regulatory Authority (TRA) to communicate between the travel agencies to take advantages from the grouping to arrange and optimize tourists’ trip which may increase their profit and reduce tourists’ travel cost. In conclusion, the used procedure could provide the planners with a useful and powerful instrument for tourism development and prosperity.

웨이퍼 핸들링을 위한 collet의 외관 비전 검사 장치 개발

In semiconductor manufacturing, small and precise tools such as collets are used during the assembly process to control and improve product quality. Monitoring the quality of the collet, such as its shape, size, and hole, is crucial for ensuring high reliability when picking up a cut wafer during the semiconductor packaging process. In this study, we propose a defect detection algorithm using image processing techniques. The application was implemented in a visual C++ environment, which enables motion control, image acquisition control, and the execution of image processing algorithms. The test and analysis of the collet inspection system yielded a defect detection rate of 99.3%.

The sacred stone from the sea. Archaeological and ethnographic perspectives on the ritual value of coral across the Pacific

ABSTRACTThe Pacific Islands offer a variety of marine environments providing peoples in the present and past with abundant coral materials, a “stone from the sea”. Archaeologists have long recognised the importance of coral in ancient contexts, whether as gravel, natural branches, squared blocks or cut‐and‐dress slabs. Coral was also used to manufacture tools such as files or pounders and incorporated in monumental ceremonial architecture as a favoured construction material and foundation offerings. However, Pacific Islanders also employed coral material for other ritual applications that remain overlooked in the literature. In this article, we consider the multiple uses of coral in the archaeological and ethnographic records of three Pacific regions: Central‐East Polynesia (CEP), New Caledonia and the Torres Strait Islands. This includes offering of coral branches, sometimes associated with cairns, paraphernalia and magic stones, also production of coral lime for body ornamentation. Using these case studies, we consider material selection, modes of deposition, archaeological and ethnographic contexts, associations with other features and artefacts, before interrogating the potential significance of these unrealised datasets. By doing so, we shed new light on the ritual value of coral and reflect on the symbolic nature and function of this material.

3D-printed EVA-based patches manufactured by direct powder extrusion for personalized transdermal therapies

In recent years, 3D printing has attracted great interest in the pharmaceutical field as a promising tool for the on-demand manufacturing of patient-centered pharmaceutical forms. Among the existing 3D printing techniques, direct powder extrusion (DPE) resulted as the most practical approach thanks to the possibility to directly process excipients and drugs in a single step. The main goal of this work was to determine whether different grades of ethylene vinyl acetate (EVA) copolymer might be employed as new feedstock materials for the DPE technique to manufacture transdermal patches. By selecting two model drugs with different thermal behavior, (i.e., ibuprofen and diclofenac sodium) we also wanted to pay attention to the versatility of EVA excipient in preparing patches for customized transdermal therapies. EVA was combined with 30 % (w/w) of each model drugs. The physicochemical composition of the printed devices was investigated through Fourier-transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analyses. FT-IR spectra confirmed that the starting materials were effectively incorporated into the final formulation, and thermal analyses demonstrated that the extrusion process altered the crystalline morphology of the raw polymers inducing the formation of crystals at lower thicknesses. Lastly, the drug release and permeation profile of the printed systems was evaluated for 48 h and showed to be dependent on the VA content of the EVA grade (74.5 % of ibuprofen released from EVA 4030AC matrix and 12.6 % of diclofenac sodium released from EVA1821A matrix). Hence, this study demonstrated that EVA and direct powder extrusion technique could be promising tools for manufacturing transdermal patches. By selecting the EVA grade with the appropriate VA content, drugs with dissimilar melting points could be printed preserving their thermal stability. Moreover, the desired drug release and permeation profile of the drug can be achieved, representing an important advantage in terms of personalized medicine.

Exposure to occupational risk factors is associated with the severity and progression of chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) results from a complex interaction between genes and the environment, and occupational exposures are an underappreciated risk factor. Until now, little research attention has been paid to the potential impact of occupational risk factor exposure on the COPD in China. The aim of this retrospective study was to analyze the role of occupational risk factor exposure on the severity and progression of COPD for exploring new prevention strategies for this disease. This study adopted a random cluster-sampling method. Five grade-A tertiary hospitals that met the inclusion criteria were selected as the survey sites, and patients with COPD hospitalized in these hospitals from January 1, 2019, to December 31, 2019, were selected as the research subjects. Data of the patients diagnosed with COPD met the Global Initiative for Chronic Obstructive Lung Disease (2019) criteria and were collected from the computerized medical record databases. Among 4082 investigated COPD patients, 1063 (26%) were found to have occupational risk factor exposure history. The top 3 industries with a large COPD case number and a history of occupational risk factor exposure ranked in the order of agriculture (including farming, forestry, animal husbandry, and fishery), manufacturing, and mining. Further multivariate logistic regression analysis indicated that when setting a low exposure level as a reference, medium and high exposure levels were correlated with the severity of COPD (odds ratio values were 2.837 and 6.201, respectively, P < .05). Linear regression analysis showed that cumulative exposure to occupational risk factors was negatively correlated with the forced expiratory volume in 1-second percentage of COPD patients, with a correlation coefficient of 0.68. Our results indicated that occupational risk factor exposure levels were related to the severity of COPD significantly. The incubation period of COPD in the exposure group was significantly shorter than that in the non-exposure group. To prevent worked-related COPD, special attention and control efforts should be taken to reduce the level of occupational risk factors such as organic dust, irritating chemicals, etc in the work environments, especially in the industries of agriculture, forestry, animal husbandry and fishery, manufacturing, and mining.

An Experience of Using Lean Production Tools in the University

The article presents the results of introducing lean manufacturing tools into the practice of a higher educational institution (Tyumen State University) within an academic year. The main research methods are timing, polling and spaghetti charting. There is mapped the organization of the course study. The effectiveness of spending time and resources when running lessons is analyzed. The issues addressed in the study relate to the productiveness of higher education institutions, their activity to be assessed not only via the characteristics of services, but also via the ways of their provision. Within our research, there was revealed a contradiction between the consumers’ (students’) expectations and the complication of the educational process. This contradiction negatively affects the university’s services quality perception and evaluation in general. The research shows that managing a higher educational institution in terms of customer orientation involves decomposition and detailed analysis of the main process – that is, of knowledge transfer. All other auxiliary processes are organized around it. Any change in an educational institution must begin with a lean mapping of all stages of knowledge transfer.

Expedient and efficient: an Early Mesolithic composite implement from Krzyż Wielkopolski

The Northern European Mesolithic is well known for the manufacture of composite tools and weapons for specialised purposes. A composite implement recovered from the Early Holocene site of Krzyż Wielkopolski 7 in Poland, dated to the Preboreal/Boreal transition, raises questions about expediency versus efficiency in the fabrication of these artefacts. Here, the authors characterise its materials and production: a bone splinter mounted on a shaft of pine wood, secured with bast ligatures coated in birch bark tar. While the manufacture of the implement's individual components can be characterised as ‘expedient’, the finished implement is, however, complex, efficient and durable.

Influencing companies to purchase lower noise tool consumables?

This paper shows how targeted basic research and existing regulations can influence duty holders (business owners) to use lower noise consumables on their power tools (saws, drills, grinders). We will show; (1) how existing regulations should change buying habits, (2) why lower noise consumables should be the standard in some industries, (3) how target basic research inform enforcement, (4) how to influence industry through advice and, (5) potential enforcement. New data will show it is possible to get a 5 dB reduction by buying the right combination of grinder products. The paper describes a regulatory method that combines research and enforcement to reduce noise risk. The paper may be of interest to, health and safety regulators, tool manufacturers, noise consultants, and purchasing managers.

Numerical investigation of the effects of model and operator uncertainties on component-based transfer path analysis methods with substructuring applied to aircraft-like components

Hydraulic pumps are considered to have a major contribution to the structure borne noise generated inside aircrafts. Methods such as Component-Based Transfer Path Analysis (CB-TPA) are promising tools for aircraft manufacturers to build internal processes for the specification, design and validation of the impact of vibrating systems on new aircrafts. However, the experimental applicability of these methods remains limited due to some experimental difficulties. CB-TPA' formulation is based on dynamical quantities, which require the determination of terms related to rotational degrees of freedom. Virtual Point (VP) or Equivalent Multi-Point Connection (EMPC) methods are commonly employed for this purpose, but both result in more cumbersome experimental set-ups and increased measurement uncertainties. The implementation of these methods is difficult in the case of a flat and thin receiving structure as commonly encountered in aircraft applications, since in-plane translational excitations have to be applied and the access to the vibrating system/structure interface points is limited. In this work, a decoupling procedure is used to overcome these issues. A numerical model is used to investigate the influence of model and operator uncertainties on the CB-TPA' predictions, when the dynamical quantities are provided by VP and EMPC methods including the decoupling procedure.

Conformal 3D Material Extrusion Additive Manufacturing for Large Moulds

Industrial engineering applications often require manufacturing large components in composite materials to obtain light structures; however, moulds are expensive, especially when manufacturing a limited batch of parts. On the one hand, when traditional approaches are carried out, moulds are milled from large slabs or laminated with composite materials on a model of the part to produce. In this case, the realisation of a mould leads to adding time-consuming operations to the manufacturing process. On the other hand, if a fully additively manufactured approach is chosen, the manufacturing time increases exponentially and does not match the market’s requirements. This research proposes a methodology to improve the production efficiency of large moulds using a hybrid technology by combining additive manufacturing and milling tools. A block of soft material such as foam is milled, and then the printing head of an additive manufacturing machine deposits several layers of plastic material or modelling clay using conformal three-dimensional paths. Finally, the mill can polish the surface, thus obtaining a mould of large dimensions quickly, with reduced cost and without needing trained personnel and handcraft polishing. A software tool has been developed to modify the G-code read by an additive manufacturing machine to obtain material deposition over the soft mould. The authors forced conventional machining instructions to match those of an AM machine. Thus, additive deposition of new material uses 3D conformal trajectories typical of CNC machines. Consequently, communication between two very different instruments using the same language is possible. At first, the code was tested on a modified Fused Filament Fabrication machine whose firmware has been adapted to manage a milling tool and a printing head. Then, the software was tested on a large machine suitable for producing moulds for the large parts typical of marine and aerospace engineering. The research demonstrates that AM technologies can integrate conventional machinery to support the composite materials industry when large parts are required.