| 1. |
- Hakeem, Abbas Saeed, et al.
(författare)
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Synthesis and characterization of alkaline earth and rare earth doped sialon Ceramics by spark plasma sintering
- 2021
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Ingår i: International journal of refractory metals & hard materials. - : Elsevier. - 0263-4368. ; 97
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Tidskriftsartikel (refereegranskat)abstract
- Several sialon ceramics compositions were synthesized by selecting metal oxides (MOs) in the nanosize range as additives in the oxynitride network. Nanosized precursors, including Si3N4, SiO2, AlN, Al2O3, and MO (MO =MgO, CaO, SrO, BaO, Y2O3, La2O3, CeO2, Nd2O3, Eu2O3, Dy2O3, Er2O3 and Yb2O3,) were used in the present study. Probe sonication and spark plasma sintering techniques were used for mixing the powder precursors and subsequent synthesis of sialon ceramics at a relatively low temperature of 1500 ◦C. Formation of α-sialon(general formula represented by Mm/vSi12-(m+n)Alm+nOnN16-n) was investigated for m and n values of 1.1 and 0.6, respectively and their structural, morphological, thermal, and mechanical properties were evaluated. The synthesized samples were characterized using X-ray diffractometry and field emission scanning electron microscopy to study the effect of the MOs on the microstructure and resulting densification, hardness, fracture toughness, thermal expansion, and thermal conductivity. The sialon samples synthesized using the selected MOs exhibited similar relative densities in the range of 96 to 99% among all the samples and Vickers hardness (HV10) values, in the range of 15 to 20.8 GPa, depending on the type of MO. However, RE MOs exhibited a higher HV than AE MOs.Fracture toughness (KIc) was ~4 MPa⋅m1/2 for most of the samples, but the sample doped with Yb2O3 had the highest KIc of 6.3 MPa⋅m1/2. The thermal conductivity decreased as the atomic number (atomic radii) of the AE increases and in the case of RE exhibited a random tendency. On the other hand, the thermal expansion coefficient increased with increasing atomic radii of the AE, and a mixed trend, with values in the range of 2.63 to2.83 ppm⋅K-1, was observed for RE doped sialon ceramics. These behaviors are attributed to the resulting morphology and structure of alpha sialon comprised of both equiaxed and elongated grains. The properties of these sialon ceramics could be tailored by the proper selection of suitable precursors and synthesis parameters.
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| 2. |
- Irshad, Hafiz Musammil, et al.
(författare)
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Effect of Ni content and Al2O3 particle size on the thermal and mechanical properties of Al2O3/Ni composites prepared by spark plasma sintering
- 2018
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Ingår i: International journal of refractory metals & hard materials. - : Elsevier. - 0263-4368. ; 76, s. 25-32
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Tidskriftsartikel (refereegranskat)abstract
- Alumina-nickel composites were prepared by carrying out spark plasma sintering (SPS) of nano-sized and micro-sized Al2O3particles with 15–45 wt% Ni powders. The powder materials were sintered at a temperature of1400 °C under a constant uniaxial pressure of 50 MPa. FESEM micrographs of the products showed uniformlydispersed nickel inclusions in both matrices at intergranular positions. Presence of Al2O3as the major phasealong with Ni as the minor phase was confirmed using XRD analysis. Thermal and mechanical properties of thenano- and micro-sized Al2O3/Ni composites were investigated. The thermal conductivity of nano-sized aluminacomposites was seen to increase with the increase in nickel content, however, an opposite trend was observed formicro-sized alumina-based composites. Moreover, thermal conductivities of all the composites decreased withincrease in temperature. The composites also showed high hardness and fracture toughness values of up to19.6 GPa and 4.71 MPa ∗ m1/2, respectively, and relative density values, between 79 and 99%, that decreasedwith increasing Ni content. Furthermore, the nano-sized Al2O3/Ni composites showed thermal and mechanicalproperties superior to those of the micro-sized Al2O3/Ni composite.
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| 3. |
- Taj, Soonh, et al.
(författare)
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IoT-based supply chain management : A systematic literature review
- 2023
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Ingår i: Internet of Things. - : Elsevier. - 2542-6605. ; 24
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Forskningsöversikt (refereegranskat)abstract
- Supply Chain Management (SCM) consists of handling and optimizing all the facets of the supply chain process of goods and services. Modern SCM is reaping the benefits from the emerging and growing Internet of Things (IoT) field. IoT technology can automate and digitalize the supply chain processes to get maximum operational efficiencies by reducing operating costs. The mass proliferation of IoT devices has revolutionized supply chains. IoT devices in the supply chain process track and trace shipments using the latest real-time monitoring technologies, including GPS. IoT devices are also used for asset management using NFC technology and RFID tags. Overall, IoT devices are used in almost every stage of the supply chain process. Research on IoT-based SCM is still in the growing phase. A lot of technical work is currently being published on IoT-based SCM, but a few Systematic Literature Reviews (SLRs) have been found for IoT-based SCM. The holistic view of IoT-based SCM with detailed analysis is still not reported in any review. This paper addresses this knowledge gap by presenting an SLR on IoT-based SCM with a detailed analysis of IoT-based SCM from 2018 to 2022. This review covers the aspects of IoT-based SCM, such as application domains, technologies, sensors, and devices used to implement IoT-based SCM systems. The SLR findings will assist future researchers and practitioners interested in IoT-based SCM by offering an in-depth study of the literature on IoT-based SCM, including helpful insights on challenges, benefits, and economic and business implications.
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| 4. |
- Adamopoulos, Stergios, et al.
(författare)
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Acoustic properties of acetylated wood under different humid conditions and its relevance for musical instruments
- 2018
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Ingår i: Proceedings of the 9th European Conference on Wood Modification 2018, Arnhem, The Netherlands. - The Netherlands : Practicum. ; , s. 236-243
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Konferensbidrag (refereegranskat)abstract
- In musical instrument making, less expensive wood species and materials with good characteristics and acoustical properties can provide potentials to find alternatives to the traditional exotic wood species used today. Modified wood could be such a choice if shows similar sound characteristics to wood coming from endangered and expensive tropical species with problematic commercial availability. In musical instruments, the overall functionality depends on the contribution of wood to different material performance indexes like sound radiation coefficient (R), characteristic impedance (z) and acoustic conversion efficiency (ACE). In this study, the performance indexes were measured for acetylated beech, maple and radiata pine and compared with these obtained for the reference wood materials maple, mahogany, alder and ash. A non-destructive free-free flexural vibration test method was used at constant temperature (20oC) but in different humid conditions- dry (35% RH), standard (65% RH) and wet (85% RH). Dimensional changes in the different humid conditions were also taken in account. Acetylated wood showed lower EMC with higher dimensional stability at each humidity level as compared with the reference wood materials. These properties are considered important factors for making quality musical instruments. Based on the acoustical properties, acetylated wood materials, especially radiata pine, showed good potential for use for musical instruments where specific characteristics of sound are required. However, the other types of acetylated wood can also be used for specific musical instruments.
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| 5. |
- Ahmed, Ali, 1977-, et al.
(författare)
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Are gay men and lesbians discriminated against in the hiring process?
- 2013
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Ingår i: Southern Economic Journal. - : Southern Economic Association (SEA). - 0038-4038 .- 2325-8012. ; 79:3, s. 565-585
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Tidskriftsartikel (refereegranskat)abstract
- This article presents the first field experiment on sexual orientation discrimination in the hiring process in the Swedish labor market. Job applications were sent to about 4000 employers in 10 different occupations in Sweden. Gender and sexual orientation were randomly assigned to applications. The results show that sexual orientation discrimination exists in the Swedish labor market. The discrimination against the gay male applicant and the lesbian applicant varied across different occupations and appears to be concentrated in the private sector. The results also show that the gay male applicant was discriminated against in typical male-dominated occupations, whereas the lesbian applicant was discriminated against in typical female-dominated occupations. Theoretical implications are discussed
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| 6. |
- Ahmed, Ali, et al.
(författare)
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Are homosexuals discriminated against in the hiring process?
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents the first field experiment on sexual orientation discrimination in the hiring process in the Swedish labor market. Job applications were sent to about 4,000 employers in 10 different occupations in Sweden. Gender and sexual orientation were randomly assigned to applications. The results show that sexual orientation discrimination exists in the Swedish labor market. The discrimination against gays and lesbian varies across different occupations and appears only in the private sector. The results also seem to suggest a new dimension of traditional gender roles; the gay applicant was discriminated against in typical male-dominated occupations whereas the lesbian applicant was discriminated against in typical female-dominated occupations. Thus, the results suggest that gays to some extent face the same obstacles on the labor market as heterosexual women.
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| 7. |
- Ahmed, Ali, et al.
(författare)
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Are lesbians discriminated against in the rental housing market? Evidence from a correspondence testing experiment
- 2008
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Ingår i: Journal of Housing Economics. - : Elsevier BV. - 1051-1377 .- 1096-0791. ; 17:3, s. 234-238
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a field experiment, conducted over the Internet, studying possible discrimination against lesbians in the rental housing market in Sweden. We let two fictitious couples, one heterosexual and one lesbian, apply for vacant rental apartments advertised by landlords on the Internet. We then investigated whether there were differences between the couples in the number of received call-backs, invitations to further contact, and invitations to immediate showings. Our findings show no indication of differential treatment of lesbians by landlords. A discussion relating to earlier findings is provided.
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| 8. |
- Ahmed, Ali, 1977-
(författare)
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Are religious people more prosocial? : A quasi-experimental study with madrasah pupils in a rural community in India
- 2009
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Ingår i: Journal for the Scientific Study of Religion. - : Wiley. - 0021-8294 .- 1468-5906. ; 48:2, s. 368-374
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Tidskriftsartikel (refereegranskat)abstract
- Using quasi-experimental data, this article examines the relationship between religiosity and prosocial behavior. In contrast to previous studies that identify religious people by how often they attend religious services or by their self-reported religiosity, this study compares the behavior of highly devout students who are preparing to enter the clergy to the behavior of other students in a public goods game and in the dictator game. The results show that religious students were significantly more cooperative in the public goods game and significantly more generous in the dictator game than other students.
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