Investigation of the effects of linear alkyl benzene sulphonic acid modification on the temperature susceptibility and viscoelastic behaviour of bitumen

Alkil benzen’den türetilmiş amfifillerin, asfalten çökelmesini geciktirici özellikleri sebebiyle, asfalt endüstrisinde kullanıldığı bilinmektedir, ancak bu konuda yapılmış çalışmalar kısıtlıdır. Çalışma kapsamında, deterjan endüstrisinde kullanılan lineer alkil benzen sülfonik asit (LABSA) sürfaktanının bitüm ile kullanımı, penetrasyon ve yumuşama noktası deneyi ile dinamik kayma reometresi kullanılarak incelenmiştir. Farklı LABSA içerikleri ile üretilmiş numunelerin penetrasyon indeksi ve kompleks kayma modül değerleri göz önünde bulundurularak sıcaklık hassasiyeti ve viskoelastik davranışları araştırılmıştır. Ayrıca, numunelerin kısa dönem ve uzun dönem yaşlanma sonrasındaki performansları da incelenerek LABSA içeriğinin yaşlanmaya karşı etkileri irdelenmiştir. Elde edilen sonuçlara göre, LABSA kullanımının sıcaklık hassasiyetini belirgin özellikte azalttığı ve bitüme elastik davranış kazandırdığı görülmektedir. Bitüm ağırlığının %2’si oranında LABSA kullanımı, sıcaklık hassasiyeti ve elastik performans açısından en uygun sonuçları vermektedir. Bununla birlikte, LABSA modifikasyonunun bitümün yaşlanmaya karşı direncini arttırmaktadır.It is known that, alkyl benzene derived amphiphiles are used in the asphalt industry due to their retarding properties of asphaltene precipitation, but studies on this subject are limited. Within the scope of this study, the utilization of linear alkyl benzene sulfonic acid (LABSA) surfactant with bitumen was evaluated by penetration and softening point tests together with dynamic shear rheometer investigations. Considering the penetration index and complex shear modulus values of the samples produced with different LABSA contents, temperature sensitivity and viscoelastic behaviours were investigated. In addition, the performance of the samples after short-term and long-term aging was also examined, so that the effects of LABSA content against aging were studied. According to the results, it is seen that the use of LABSA significantly reduces the temperature susceptibility and improves the bitumen's elastic behaviour. Additionally, LABSA modification increased the aging resistance of the bitumen. Utilization of LABSA at the rate of 2% of bitumen weight provided the best results in terms of temperature sensitivity and elastic performance among the samples

‘Love your job!’ A psychosocial research on affective labour in the Turkish fine-dining sector

Drawing on a multi-sited psychosocial ethnography of the fine-dining sector in Istanbul, Turkey, this thesis explores the vicissitudes of love and affective labour under post-Fordism. It studies (i) discourses and imagery of love for culinary work circulating around the world, and their particular articulation in the Turkish fine dining context, (ii) how local actors are enticed by, act on, embody, reify and perform the ethos of love inscribed in these representations, and (iii) how the performance of love is implicated in cooks’ affective labour, subjectivity, wellbeing and working conditions. The thesis is based on a new research methodology developed through cross fertilisation between multi-sited organisational ethnography and psycho analytically inflected research. The fieldwork was designed to trace the ethos of love in discourses, images, artefacts and performances across culinary sites. Theoretical insights from Freud and Lacan are employed to interpret the ethnographic material, shedding light on its unconscious and affective facets. The thesis engages with post-Fordist thought, the affective labour debate and psychosocial studies. It contributes to the scholarly literature by providing a rigorous analysis and elaborate theory of symbolic identification with the post-Fordist ethos, imaginary identification with cultural representations, performance of these identifications as part of affective labour, and ambivalence toward one’s job. Intricate connections between these moments in the psychosocial process of subject formation are revealed and theorised. A novel and psychoanalytically-inflected definition of affective labour is also offered, which emerges as the performative work of reproducing individuals and collectives requiring human contact, interpersonal skills, emotion management, embodiment of cultural imagery and social roles, and love. The thesis disentangles the hegemonic ethos of post-Fordist work and develops a comprehensive theory of its affectivity

‘He pours love and you eat it’ : a psychoanalytic study of human contact and love in affective labor

This psychoanalytic study of affective labour focuses on its two central elements: human contact and love. It is based on a multi-sited organizational ethnography of the fine-dining sector in Istanbul, Turkey, where new restaurant areas known as ‘show kitchens’ place chefs in face-to-face contact with patrons. To understand the psychosocial processes of affective production, we analyze chefs’ and patrons’ experiences of encounters in and around ‘show kitchens’. We demonstrate that affect is produced through unconscious contact mediated by socio-cultural representations, which are hegemonized by the ethos of love for one’s job. We contribute to the extant literature on affective labour by studying the desirous interplay between producers and consumers of affect. Specifically, we theorize the role of the psyche in affective production, and offer a new, psychoanalytic conceptualization of affective labour. We conclude by discussing our conceptualization’s organizational and political implications

Grounding in the unconscious: “the field” in psychosocial organizational ethnography

Psychosocial research, which explores the unconscious and affective dynamics of organizational and social phenomena from critical perspectives, often adopts ethnographic methods. However, its locus, the unconscious, has an obscure, diffuse and dynamic nature that calls into question two central assumptions of conventional organizational ethnography: that an organization is a self-contained physical (research) site, and ethnographic research is best led by participant observation. The unconscious is produced by countless agents dispersed across time and space, making it impossible to readily identify a research site. Furthermore, psychosocial phenomena cannot be physically demarcated because a multitude of discourses, imagery, psyches, bodies, and objects are enmeshed in them. These raise contentious ontological, epistemological, and methodological questions for psychosocial researchers. In this article, we ruminate on “the field” in psychosocial organizational ethnography, seeking a robust epistemological and methodological approach to constructing and dwelling in an unconscious research site. Drawing on Lacanian psychoanalysis, we present a conceptual discussion of these issues and translate them into ethnographic methods illustrated by examples from the authors’ research. By critically re-evaluating the question of “the field,” we contribute to ethnographic studies of organizational phenomena with “fuzzy fields” without self-evident boundaries that draw on diverse onto-epistemologies

The effects of Covid-19 on physical medicine and rehabilitation in Turkey in the first month of pandemic

Objectives: The outbreak of novel coronavirus-2019 (COVID-19) has affected Turkey very seriously, as well as all around the world. Many urgent and radical measures were taken due to the high contagious risk and mortality rate of the outbreak. It is noteworthy that isolation recommendations and the provision of health services for pandemic have a negative impact on Physical Medicine and Rehabilitation (PMR) services. In this study, we aimed to evaluate the effects of COVID-19 on the PMR services and physiatrists immediately after the first month of pandemic in Turkey. Patients and methods: An online survey consisting of 45 items was sent to the members of the Turkish Society of Physical Medicine and Rehabilitation. The main goal of the survey was to evaluate the changes in the provided service of PMR and conditions of physiatrists one month after the first reported COVID-19 case in Turkey. Results: A total of 606 PMR specialists and residents responded to the survey. The mean number of the patients visited the outpatient clinics was 148.2 +/- 128.5 per week before the pandemic, it significantly decreased to 23.4 +/- 33.1 per week after the first month of the reported first COVID-19 case. Similarly, the mean number of the patients of inpatient service significantly decreased from 21.7 +/- 39.3 per week to 2.5 +/- 10.0 per week after the first month of the pandemic. Most of the residents (69%) reported that their training was seriously affected due to pandemic. From the economic aspect, 69.2% of the participants who were working at private hospitals reported a decrease in their monthly salary, and 21% of them were sent to an unpaid vacation. A total of 21.9% of private-practice institutions paused their services. During the first month, 46.9% of the participants were assigned to the different services such as COVID-19 inpatient service, emergency or COVID-19 outpatient clinics. According to the Republic of Turkey, Ministry of Health guideline and algorithm, 15.7% of the physicians were in the category of healthcare workers with suspected COVID-19. Conclusion: The COVID-19 pandemic affected seriously both the services and the PMR physicians as early as the first month. This effect is expected to become worse, when the duration of pandemic prolongs. Proper arrangements and measures should be planned to ameliorate the negative effects of the pandemic on the patients and PMR physicians

Antiaging Effects of Linear Alkyl Benzene Sulfonic Acid Utilization on Bitumen Modification

© 2022 American Society of Civil Engineers.The manufacture of asphalt pavements causes various environmental problems due to bitumen's hazardous nature. Aging of bitumen yields undesirable properties, which may cause several adverse effects on asphalt performance. Use of antiaging agents for bitumen modification results in improved aging resistance, hence such agents confer environmental benefits by reducing the consumption of bitumen owing to lower maintenance requirements and the reduced volume that needs to be produced. Therefore, it is important to develop new antiaging agents and investigate their benefits to the asphalt industry. This study investigated the use of different rates (1%, 2%, and 3%) of linear alkyl benzene sulfonic acid (LABSA) as a bitumen antiaging agent through chemical and rheological characterization on unaged, short-term-aged, and long-term-aged samples using Fourier transform infrared spectroscopy and dynamic shear rheometer (DSR). A chemical aging index (CAI) and various rheological aging indexes, obtained by the construction of master curves and crossover temperatures were calculated to evaluate the variation of aging effects by LABSA addition. The detailed experiments showed that LABSA-modified samples exhibited better aging resistance compared to neat (base) bitumen. Additionally, the statistical analyses of all aging indexes were investigated to obtain the relationship between chemical and rheological aging indexes. The determination coefficient (R2) and scatter index (SI) results showed that the rheological behavior of bitumen against aging could be evaluated based on chemical behavior and vice versa. Moreover, it was concluded that short-term aging and long-term aging effects should be evaluated separately to determine the relationship between different aging characteristics of samples

High and low temperature rheological characteristics of linear alkyl benzene sulfonic acid modified bitumen

© 2021 Elsevier LtdThe rheological properties of bitumen can be improved through modification with various additives. Alkyl benzene-derived amphiphiles have been considered as an effective surfactant that can help stabilizing the asphaltene structures within the bitumen. In this study, linear alkyl benzene sulfonic acid (LABSA) was investigated as a binder modifier by evaluating the rheological characteristics at different temperatures. The rheological properties of bitumen involving different rates of LABSA (1%, 2% and 3% of bitumen weight) together with neat (unmodified) bitumen as a control sample, were studied at critical temperatures using dynamic shear rheometer (DSR) and bending beam rheometer (BBR). The results pointed out that, LABSA modification exhibited increased resistance to rutting and fatigue cracking along with improved low temperature susceptibility characteristics. Furthermore, it also helped to serve heavier traffic levels compared to unmodified bitumen. Based on the study outcomes, LABSA can be considered as a potential modifier for asphalt binder, especially when the rate of utilization is chosen as 2% by bitumen weight