IX. On the heat produced by friction or compression

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Spectroscopic analysis of Turkey red oil samples as a basis for understanding historical dyed textiles

Heritage conservation science is a valuable technique for improving understanding and the preservation of historical objects. Material analysis of heritage textiles and related materials provides information about polymer and colorant degradation, and contributes to improved conservation and display practices. The re‐creation of materials following historical processes is useful for testing analytical techniques in a field where ethical constraints often limit sampling, and to also identify potential age‐related changes relative to a fresh product. Despite the broad historical interest and industrial significance of Turkey red from the late eighteenth to the nineteenth century, little about the chemical complex of these unique textiles was understood in scientific terms. This study applied modern analysis with 1H and 13C nuclear magnetic resonance (NMR) spectroscopy to investigate the conclusions reached by nineteenth century chemists, that fatty acids were a key component of the oil treatment, a unique and vital aspect of the Turkey red dyeing process. The results show that Turkey red oil samples are composed of fatty acids which tend to polymerise over time, and that modern commercial Turkey red oil has a similar composition to historical samples and a replica sample made following a nineteenth century method. This information was used to form a hypothesis for the overall Turkey red complex on the fibre, and confirmed that the experimental work of nineteenth century chemists was theoretically accurate despite their lack of precise analytical techniques. This indicates that a re‐creation and analysis approach is effective for studying heritage materials, provided the historical practice for making the original object is taken into consideration

TB/HIV Co-Infection Care in Conflict-Affected Settings: A Mapping of Health Facilities in the Goma Area, Democratic Republic of Congo

Background : HIV/AIDS and Tuberculosis (TB) are major contributors to the burden of disease in sub- Saharan Africa. The two diseases have been described as a harmful synergy as they are biologically and epidemiologically linked. Control of TB/HIV co-infection is an integral and most challenging part of both national TB and national HIV control programmes, especially in contexts of instability where health systems are suffering from political and social strife. This study aimed at assessing the provision of HIV/ TB co-infection services in health facilities in the conflict-ridden region of Goma in Democratic Republic of Congo. Methods: A cross-sectional survey of health facilities that provide either HIV or TB services or both was carried out. A semi-structured questionnaire was used to collect the data which was analysed using descriptive statistics. Results: Eighty facilities were identified, of which 64 facilities were publicly owned. TB care was more available than HIV care (in 61% vs. 9% of facilities). Twenty-three facilities (29%) offered services to co-infected patients. TB/HIV co-infection rates among patients were unknown in 82% of the facilities. Only 19 facilities (24%) reported some coordination with and support from concerned diseases’ control programmes. HIV and TB services are largely fragmented, indicating imbalances and poor coordination by disease control programmes. Conclusion: HIV and TB control appear not to be the focus of health interventions in this crisis affected region, despite the high risks of TB and HIV infection in the setting. Comprehensive public health response to this setting calls for reforms that promote joint TB/HIV co-infection control, including improved leadership by the HIV programmes that accuse weaknesses in this conflict-ridden region

The 'absolute existence' of phlogiston: the losing party's point of view.

Long after its alleged demise, phlogiston was still presented, discussed and defended by leading chemists. Even some of the leading proponents of the new chemistry admitted its ‘absolute existence’. We demonstrate that what was defended under the title ‘phlogiston’ was no longer a particular hypothesis about combustion and respiration. Rather, it was a set of ontological and epistemological assumptions and the empirical practices associated with them. Lavoisier’s gravimetric reduction, in the eyes of the phlogistians, annihilated the autonomy of chemistry together with its peculiar concepts of chemical substance and quality, chemical process and chemical affinity. The defence of phlogiston was the defence of a distinctly chemical conception of matter and its appearances, a conception which rejected the chemist’s acquaintance with details and particularities of substances, properties and processes and his skills of adducing causal relations from the interplay between their complexity and uniformity

Alkaline air: changing perspectives on nitrogen and air pollution in an ammonia-rich world

Ammonia and ammonium have received less attention than other forms of air pollution, with limited progress in controlling emissions at UK, European and global scales. By contrast, these compounds have been of significant past interest to science and society, the recollection of which can inform future strategies. Sal ammoniac (nūshādir, nao sha) is found to have been extremely valuable in long-distance trade (ca AD 600–1150) from Egypt and China, where 6–8 kg N could purchase a human life, while air pollution associated with nūshādir collection was attributed to this nitrogen form. Ammonia was one of the keys to alchemy—seen as an early experimental mesocosm to understand the world—and later became of interest as ‘alkaline air’ within the eighteenth century development of pneumatic chemistry. The same economic, chemical and environmental properties are found to make ammonia and ammonium of huge relevance today. Successful control of acidifying SO2 and NOx emissions leaves atmospheric NH3 in excess in many areas, contributing to particulate matter (PM2.5) formation, while leading to a new significance of alkaline air, with adverse impacts on natural ecosystems. Investigations of epiphytic lichens and bog ecosystems show how the alkalinity effect of NH3 may explain its having three to five times the adverse effect of ammonium and nitrate, respectively. It is concluded that future air pollution policy should no longer neglect ammonia. Progress is likely to be mobilized by emphasizing the lost economic value of global N emissions ($200 billion yr−1), as part of developing the circular economy for sustainable nitrogen management

Can biomedical and traditional health care providers work together? Zambian practitioners' experiences and attitudes towards collaboration in relation to STIs and HIV/AIDS care: a cross-sectional study

BACKGROUND: The World Health Organization's World health report 2006: Working together for health underscores the importance of human resources for health. The shortage of trained health professionals is among the main obstacles to strengthening low-income countries' health systems and to scaling up HIV/AIDS control efforts. Traditional health practitioners are increasingly depicted as key resources to HIV/AIDS prevention and care. An appropriate and effective response to the HIV/AIDS crisis requires reconsideration of the collaboration between traditional and biomedical health providers (THPs and BHPs). The aim of this paper is to explore biomedical and traditional health practitioners' experiences of and attitudes towards collaboration and to identify obstacles and potential opportunities for them to collaborate regarding care for patients with sexually transmitted infections (STIs) and HIV/AIDS. METHODS: We conducted a cross-sectional study in two Zambian urban sites, using structured questionnaires. We interviewed 152 biomedical health practitioners (BHPs) and 144 traditional health practitioners (THPs) who reported attending to patients with STIs and HIV/AIDS. RESULTS: The study showed a very low level of experience of collaboration, predominated by BHPs training THPs (mostly traditional birth attendants) on issues of safe delivery. Intersectoral contacts addressing STIs and HIV/AIDS care issues were less common. However, both groups of providers overwhelmingly acknowledged the potential role of THPs in the fight against HIV/AIDS. Obstacles to collaboration were identified at the policy level in terms of legislation and logistics. Lack of trust in THPs by individual BHPs was also found to inhibit collaboration. Nevertheless, as many as 40% of BHPs expressed an interest in working more closely with THPs. CONCLUSION: There is indication that practitioners from both sectors seem willing to strengthen collaboration with each other. However, there are missed opportunities. The lack of collaborative framework integrating maternal health with STIs and HIV/AIDS care is at odds with the needed comprehensive approach to HIV/AIDS control. Also, considering the current human resources crisis in Zambia, substantial policy commitment is called for to address the legislative obstacles and the stigma reported by THPs and to provide an adequate distribution of roles between all partners, including traditional health practitioners, in the struggle against HIV/AIDS

BEMERKUNGEN über das Radical der Salzsäure

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LES BOITIERS AUTOLIGATURANTS

LYON1-BU Santé Odontologie (693882213) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF