M. Atar, H. Keskin, S. Korkut and D.S. Korkut
The purpose of this paper is to investigate how impregnation with boron compounds affects the surface hardness of varnished wood materials.
Abstract
Purpose
The purpose of this paper is to investigate how impregnation with boron compounds affects the surface hardness of varnished wood materials.
Design/methodology/approach
Test samples were prepared from Scotch pine, Oriental spruce, and Uludag fir, which met the requirements of ASTM D 358.These samples were impregnated with boric acid (Ba) and borax (Bx) using a vacuum technique, according to ASTM D 1413 guidelines. After impregnation, surfaces were coated with cellulosic, synthetic, polyurethane, water‐based, acrylic, and acid‐hardening varnishes in accordance with ASTM D 3023 guidelines. Surface hardnesses of specimens after the varnishing process were determined, in accordance with ASTM D 4366 guidelines.
Findings
Surface hardness was greatest for samples of spruce treated with Ba and polyurethane varnish, and lowest for samples of Scotch pine treated with Bx and synthetic varnish. With regard to wood type, impregnation material, and varnish type, surface hardness was greatest for Oriental spruce impregnated with Ba and polyurethane varnish and lowest for Scotch pine impregnated with Ba and synthetic varnish. Thus, impregnation with boron compounds increased the surface hardness of the varnished wood.
Research limitations/implications
A protective coating (such as varnish) has limited resistance to external effects and the lifetime of the coating will be determined by the type and severity of conditions to which it is exposed.
Practical implications
Types of varnishes, wood materials, and impregnation chemicals affect surface hardness and can influence the usefulness of wood materials, where surface hardness values are important.
Originality/value
The study results reported in the paper help address the lack of research in this field and should be informative, in particular, for manufacturers and consumers in the furniture and decoration sector.
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Efrida Basri, Resa Martha, Ratih Damayanti, Istie Rahayu, Wayan Darmawan and Philippe Gérardin
The surface characteristics of thermally and chemically modified wood, such as surface roughness, surface free energy (SFE) and wettability, are important properties that…
Abstract
Purpose
The surface characteristics of thermally and chemically modified wood, such as surface roughness, surface free energy (SFE) and wettability, are important properties that influence further manufacturing processes such as gluing and coating. The aim of this paper was to determine the influence of the surface roughness of thermally and chemically modified teak wood on their SFE, wettability and bonding quality for water-based acrylic and solvent-based alkyd varnishes. In addition, durability against subterranean termites in the field of these modified teak woods was also investigated to give a valuable information for their further application.
Design/methodology/approach
The woods tested in this study were fast-growing teak woods that were prepared in untreated and treated with furfuryl alcohol (FA), glycerol maleic anhydride (GMA) and thermal. SFE values were calculated using the Rabel method. The wettability values were measured based on the contact angle between varnish liquids and wood surfaces using the sessile drop method, and the Shi and Gardner model model was used to evaluate the wettability of the varnishes on the wood surface. The bonding quality of the varnishes was measured using a cross-cut test based on ASTM 3359-17 standard. In addition, durability against subterranean termites in the field of these modified teak woods was also investigated according to ASTM D 1758-06.
Findings
The results showed that furfurylated and GMA-thermal 220°C improved the durability of teak wood against termites. The furfurylated teak wood had the roughest surface with an arithmetic average roughness (Ra) value of 15.65 µm before aging and 27.11 µm after aging. The GMA-thermal 220°C treated teak wood was the smoothest surface with Ra value of 6.44 µm before aging and 13.75 µm after aging. Untreated teak wood had the highest SFE value of 46.90 and 57.37 mJ/m2 before and after aging, respectively. The K values of untreated and treated teak wood increased owing to the aging treatment. The K values for the water-based acrylic varnish were lower than that of the solvent-based alkyd varnish. The untreated teak wood with the highest SFE produced the highest bonding quality (grades 4–5) for both acrylic and alkyd varnishes. The solvent-based alkyd varnish was more wettable and generated better bonding quality than the water-based acrylic varnish.
Originality/value
The originality of this research work is that it provides evaluation values of the durability and SFE. The SFE value can be used to quantitatively determine the wettability of paint liquids on the surface of wood and its varnish bonding quality.
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Ezgi Aktar Demirtas, Ozgul Sevval Gultekin and Cigdem Uskup
With the emergence of the COVID-19 pandemic, the production shortage of personal protective equipment (PPE), such as surgical masks, has become increasingly significant. It is…
Abstract
Purpose
With the emergence of the COVID-19 pandemic, the production shortage of personal protective equipment (PPE), such as surgical masks, has become increasingly significant. It is vital to quickly provide high-quality, hygienic PPE during pandemic periods. This comprehensive case study aims to confirm that Kaizen and 5S applications reduce wastage rates and stoppages, which as a result, created a more efficient and sustainable workplace in a small–mediumenterprise (SME) producing PPE in Turkey.
Design/methodology/approach
The method for this case is discussed with the help of a flowchart using the DMAIC cycle: D-define, M-measure, A-analyse, I-improve and C-control.
Findings
The total stoppages due to fishing line, gripper, piston and yarn welding have decreased by approximately 42.4%. As a result of eliminating wasted time and reduced changeovers, a total of 5,502 min have been saved per month. This increased production of approximately 10.55% per month, led to an addition of 506,184 units.
Originality/value
The use of lean manufacturing (LM), Six Sigma, Lean Six Sigma and continuous improvement methodologies are not common in textile SMEs. Based on the current literature reviewed, to the best of the authors’ knowledge, this is the first comprehensive case study that combines statistical tools, such as hypothesis tests and LM practices, in the production process for a PPE company operating as a textile SME.
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Jugraj Singh Randhawa and Inderpreet Singh Ahuja
The purpose of this paper is to present the comprehensive literature review on 5S and suggest possible gaps from the point of view of researchers and practitioners. The manuscript…
Abstract
Purpose
The purpose of this paper is to present the comprehensive literature review on 5S and suggest possible gaps from the point of view of researchers and practitioners. The manuscript presents the overview of 5S implementation and highlights the achievements realized from deployment of 5S initiatives for sustainable performance of organizations.
Design/methodology/approach
The paper critically examines the literature on 5S, analyzes and reviews it systematically. The study highlights the critical barriers and success factors for sustainable 5S implementation in the organizations in the competitive world.
Findings
5S is an outstanding Japanese philosophy for the development of any type organization all over the world. This study bring out the concept of 5S, requirements for its holistic implementation, relationship with other lean tools, benefits, success factors and obstacles in 5S implementation. The significant contributions through 5S initiatives in the organization like production, quality, safety and effective utilization of workspace for the sustained organizational improvement have also been highlighted in the study.
Practical implications
The literature on assortment of 5S technique has been so far very limited. The present paper reviews large number of research publications related to 5S to highlight the significance of 5S philosophy in the sustainable organizational improvement across the world. It foregrounds the approach advised by the various researchers, practitioners and appraises censoriously the reason behind the demand of 5S program in the organization. The needful steps and obstacles are also foreground for the effective implementation of 5S in the organization.
Originality/value
The paper presents a comprehensive review of literature publications in the area of 5S and their assortment to develop an understanding of the significance and implementation of 5S in the organizations. The paper will be helpful or useful to researchers, safety executives, development professionals and managers in the organizations.
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Brano Glumac and Thomas P. Wissink
This paper aims to report on homebuyers’ preferences and willingness to pay for installed home photovoltaic systems. Their influence on the market position of a dwelling is…
Abstract
Purpose
This paper aims to report on homebuyers’ preferences and willingness to pay for installed home photovoltaic systems. Their influence on the market position of a dwelling is relatively unknown. Considering that expected lifespan of photovoltaic systems is at least 25 years, it is likely that many dwellings with a photovoltaic system will enter the housing market.
Design/methodology/approach
Few houses with installed photovoltaic systems have been sold in the market to date. Lack of real market data imposes a method based on the stated preference data. Therefore, the general preferences toward photovoltaic systems are determined by a discrete choice model based on responses of 227 homebuyers in the Eindhoven region, The Netherlands. Further, the model estimates were used to assess the indirect willingness to pay for home photovoltaic systems. This initial willingness to pay is further reassessed with the direct willingness to pay collected in an open-ended questionnaire format.
Findings
Results of the model show that the homebuyers’ preferences for home photovoltaic systems are large and significant. In addition to general preferences, this article reports on the taste heterogeneity carried out by separating observations based on the respondents’ characteristics. For example, photovoltaic systems are more appealing to homebuyers in more urban or central neighbourhoods. Further, the results of the direct survey lead to the conclusion that people are probably willing to pay close to the replacement value of the system and only 22 per cent of all respondents did not want to pay anything for the installed photovoltaic system.
Research limitations/implications
These findings are exploratory and they raise a number of questions for further investigations, such as those regarding the real estate value of the installed photovoltaic systems. The reported findings must be regarded as local, thus further research is necessary to understand the impact on European housing markets.
Practical implications
Preferences and willingness to pay for home photovoltaic systems can provide a variety of economic, social and political recommendations to different interested parties such as homeowners, buyers, realtors, retailers, energy companies and governments. For instance, a homeowner would like to know what would be the effect of a photovoltaic system on the housing market.
Originality/value
As per the knowledge of authors, this is the first paper to estimate the impact of an installed photovoltaic system on housing choice, measured by stated choice data in the local housing market. It expands the existing body of knowledge for increasingly important issues of valuing and measuring preferences for photovoltaic systems installed on dwellings.
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Shaman Gupta and Sanjiv Kumar Jain
– The purpose of this paper is to use the 5S tool to assist a small-scale manufacturing organization to become more productive and more efficient.
Abstract
Purpose
The purpose of this paper is to use the 5S tool to assist a small-scale manufacturing organization to become more productive and more efficient.
Design/methodology/approach
A simple approach has been adopted to create the teams for implementing 5S. Cause-and-effect diagram has been studied for shop floor analysis. Later, four data collection methods have been used to ensure right implementation of the 5S.
Findings
In the frames of this case study, it has been analyzed that implementation of “5S” resulted in overall improvement of the organization. With the implementation of “5S”, major benefits in the form of tool searching time have been achieved. Tool searching time from shop floor has been reduced from 30 minutes to 5 minutes. “5S” audit has been conducted in the organization. “5S” audit score has been increased from 7 (Week 1) to 55 (Week 20).
Practical implications
5S is a powerful tool and can be implemented in various industries whether micro, small, medium or large. Implementation of 5S has large horizontal development and can be implemented in all the workstations of an organization.
Originality/value
The publications and case study presented in this paper will be useful to researchers, professionals and others concerned with this subject to understand the significance of 5S.
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Erman Ulker, Sıla Ovgu Korkut and Mehmet Sorgun
The purpose of this paper is to solve Navier–Stokes equations including the effects of temperature and inner pipe rotation for fully developed turbulent flow in eccentric annuli…
Abstract
Purpose
The purpose of this paper is to solve Navier–Stokes equations including the effects of temperature and inner pipe rotation for fully developed turbulent flow in eccentric annuli by using finite difference scheme with fixing non-linear terms.
Design/methodology/approach
A mathematical model is proposed for fully developed turbulent flow including the effects of temperature and inner pipe rotation in eccentric annuli. Obtained equation is solved numerically via central difference approximation. In this process, the non-linear term is frozen. In so doing, the non-linear equation can be considered as a linear one.
Findings
The convergence analysis is studied before using the method to the proposed momentum equation. It reflects that the method approaches to the exact solution of the equation. The numerical solution of the mathematical model shows that pressure gradient can be predicted with a good accuracy when it is compared with experimental data collected from experiments conducted at Izmir Katip Celebi University Flow Loop.
Originality/value
The originality of this work is that Navier–Stokes equations including temperature and inner pipe rotation effects for fully developed turbulent flow in eccentric annuli are solved numerically by a finite difference method with frozen non-linear terms.
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The purpose of this paper is to derive the dyadic representations of Green’s function in lossy medium because of the electric current dipole source radiating in close proximity of…
Abstract
Purpose
The purpose of this paper is to derive the dyadic representations of Green’s function in lossy medium because of the electric current dipole source radiating in close proximity of a PEC wedge and to reveal the effect of conductivity on the scattered electric field.
Design/methodology/approach
By using the scalarization procedure, the paraxial fields are obtained first and then scalar Green’s functions are used to derive asymptotic forms of the dyadic Green’s functions. The problem is also analyzed by the image theory and analytical derivations are compared. However, analytically calculated results are validated with FEKO, a commercially available numerical electromagnetic field solver.
Findings
The results indicate that excellent agreement is observed between analytical and numerical results. Moreover, it is found that the presence of conductivity introduces a reduction in scattered electric fields.
Originality/value
Asymptotically derived forms presented in this study can be used to calculate field distributions in the paraxial region of a wedge in a lossy medium.
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Veli Yilanci and Ugur Korkut Pata
This study aims to investigate the impact of the rise in coronavirus disease 2019 (COVID-19) cases on stock prices, exchange rates and sovereign bond yields in both Brazil and…
Abstract
Purpose
This study aims to investigate the impact of the rise in coronavirus disease 2019 (COVID-19) cases on stock prices, exchange rates and sovereign bond yields in both Brazil and India.
Design/methodology/approach
The authors employ the wavelet transform coherence (WTC) and continuous wavelet transform (CWT) techniques on daily data from March 17, 2020 to May 8, 2021.
Findings
The findings show that COVID-19 has no impact on exchange rates but slightly increases sovereign bond yields from 2021 onwards. In contrast, the effect of COVID-19 on stock prices is quite high in both countries. There is a considerable consistency between COVID-19 cases and stock prices across different time–frequency dimensions. The rise in COVID-19 cases has an increasing effect on stock prices in Brazil and India, especially in the high-frequency ranges.
Originality/value
As far as the authors know, no prior study has simultaneously analyzed the effects of the COVID-19 pandemic on exchange rates, stock prices and sovereign bonds in Brazil and India.
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Hakan Keskin, Musa Atar, Süleyman Korkut and Derya Sevim Korkut
The purpose of this paper is to determine the effect of Imersol Aqua impregnation of Scotch pine, Oriental spruce, and Uludağ fir on the surface adhesion strength of various types…
Abstract
Purpose
The purpose of this paper is to determine the effect of Imersol Aqua impregnation of Scotch pine, Oriental spruce, and Uludağ fir on the surface adhesion strength of various types of varnishes. The finding obtained would benefit the manufacturers of building materials and furniture, where the surface adhesion strength of water‐based varnishes is a concern.
Design/methodology/approach
For this purpose, test samples were prepared from Scotch pine, Oriental spruce, and Uludağ fir woods that met the requirements of ASTM D 358. The samples were impregnated with Imersol Aqua using short‐, medium‐, and long‐term immersion techniques according to ASTM D 1413 and the manufacturer's instructions. After impregnation, surfaces were coated with synthetic, acrylic, polyurethane, and water‐based varnishes in accordance with ASTM D 3023 standards. After the varnishing process, the adhesion strength of the samples was determined in accordance with ASTM D 4541.
Findings
It was also found that among the wood samples, the adhesion strength was highest in Scotch pine and lowest in Uludağ fir. The synthetic varnish produced the highest adhesion strength, whereas polyurethane and acrylic varnishes had the lowest adhesion strength. The adhesion strength was highest after medium‐term immersion and lowest after long‐term dipping. The highest adhesion strength (4.299 MPa) was produced by a combination of Scotch pine, medium‐duration immersion, and the use of a wood‐based varnish. The lowest adhesion strength (2.090 MPa) resulted from the combination of Uludağ fir, long‐term immersion, and a water‐based varnish.
Research limitations/implications
Impregnating woods using materials with appropriate water repellent, biotic, and abiotic effects before the application of varnishes and paints is important for long‐term protection against photochemical degradation, dimensional changes, biological factors, and fire.
Practical implications
The effect of a varnish on surface adhesion strength can determine the usefulness of the varnish.
Originality/value
Improving surface adhesion of some varnishes via medium‐term impregnation with Imersol Aqua impregnation should be used on Scotch pine, Oriental spruce, and Uludağ fir woods which could be used in the manufacturing of building materials and furniture, where the surface adhesion strength of water‐based varnishes is a concern.