The effect of organic friction modifiers on ZDDP tribofilm

In recent years a major concern in lubricant formulation has become the design of lubricants that can deliver very low friction and thus reduce energy consumption. This can be achieved in two main ways, by lowering the effective viscosity of lubricants and thus reducing hydrodynamic friction, and by reducing boundary friction through the use of friction modifier additives (FMs). Both approaches carry risk. Reducing lubricant viscosity can result in thinner lubricant films and this can lead to excessive wear, while some FM additives may inhibit the action of other lubricant additives present in a formulation. The aim of this thesis was to investigate the behaviour of one type of organic friction modifier, the Ethomeens, in rubbing tribological contacts, with respect to their effect on the widely-used antiwear additive zinc dialkyldithiophosphate (ZDDP). Of particular interest was to determine the extent to which Ethomeens reduce friction with ZDDP and to see whether they damage the protective antiwear films formed by ZDDPs. The tribofilm-forming ability and friction properties of a range of different types of ZDDP was studied. As in previous work, it was found that most ZDDPs rapidly form thick tribofilms with a pad-like structure on rubbed surfaces and these significantly increase friction in mixed/boundary lubrication. A new class of ZDDP was identified based on a predominantly tertiary alkyl structure. This forms tribofilms more rapidly that other ZDDPs but its films appear to be unstable and are lost during prolonged rubbing. Parallel study of the topography of ZDDP tribofilms using three different methods showed that ZDDP tribofilm topography is most reliably characterised using atomic force microscopy (AFM). 2 Transmission electron microscopy (TEM) and X-ray near edge spectroscopy (XANES) were used to characterise ZDDP tribofilms. It was found that care must be taken in preparation of samples for TEM analysis since some commonly-used methods cause considerable damage to the films under study. Using TEM, the ZDDP film studied was found to be crystalline and, using XANES, to be composed primarily of zinc orthophosphate. The immersion of pre-formed ZDDP tribofilms in Ethomeen solutions produced an immediate reduction in boundary friction and also some loss of the ZDDP film. The extent of both of these effects was found to be strongly dependent on the molecular structure of the Ethomeen and in particular its number of ethoxy groups. Ethomeens with just two ethoxy groups gave a lower reduction in friction but more removal of the ZDDP tribofilm that those with 15 ethoxy groups. This is believed to result from the easier access of the Ethomeen with fewer ethoxy groups to the ZDDP tribofilm surface. Overall the study illustrates the need to balance carefully the competing roles of different lubricant additives in the design of low friction lubricantsOpen Acces

Narses i Longobardowie

Narses po raz pierwszy zetknął się z Longobardami najprawdopodobniej, kiedy walczyli pod jego komendą w trakcie kampanii przeciw Ostrogotom z 552 r. Choć okazali się dzielnymi żołnierzami, to potem dopuścili się licznych ekscesów wobec ludności cywilnej i zostali wydaleni do swojej ojczystej Panonii. Według części źródeł (np. Izydor z Sewilli, Liber pontificalis) Narses zaprosił Longobardów do Italii w 568, chcąc zemścić się na cesarzowej Zofii. Tej wersji wydarzeń nie potwierdza jednak większość najwcześniejszych źródeł (Mariusz z Avenches, Grzegorz z Tours, źródła bizantyńskie). Narracji o konszachtach wodza z Longobardami nie można jednak całkowicie odrzucić, ze względu na fakt, że znaleźć ją można w wielu źródłach niezależnych od siebie i mimo wszystko stosunkowo wiarygodnych. W nawiązaniu do hipotezy Neila Christiego można zaproponować jej rozwinięcie, które godziłoby sprzeczne przekazy i rozwiązywało problem w postaci sprzeczności ewentualnego celowego osiedlania Longobardów w Italii z niechętną barbarzyńcom polityką prowadzoną w tym czasie przez cesarstwo. Być może Narses nawiązał kontakty z Longobardami w dobrej wierze, lecz zrobił to wbrew woli pary cesarskiej, co poskutkowało jego odwołaniem. Możliwe, próba osiedlenia ludu jako sojuszników, nie była skutkiem zaproszenia, a jedynie nieudaną próbą uporządkowania stanu faktycznego, spowodowanego ich samowolnym wkroczeniem na terytorium półwyspu.First contact between Narses and Lombards took place probably during the campaign againist Ostrogoths in 552 when Lombardsfought under his command. They seemed to be brave soldiers but simultaneously became authors of many assaults on local people and were sent back to their native Pannonia. According to some sources (e.g. Isidore of Sevilla, Liber pontificalis) Narses invited Lombards to Italy in 568 because he wanted to take his revenge on empress Sophia. This version however is not confirmed by the majority of earliest sources (e.g. Marius of Avenches, Gregory of Tours, all byzantine sources). Nonetheless the narration about collaboration between the byzantine commander and Lombards should not be all rejected because it is present in many independent and quite reliable sources. In connection to the hypothesis created by Neil Christie there is possibility to propose its extension which could unite contradict narrations. This extension could solve the problem which is contradiction between hypothetical deliberate settling of Lombards and contemporary policy of empire under Justin II which was very unfavorable for barbarians. It is possible that Narses contacted with Lombards in good faith, but did it against the will of imperial pair. The result was his removal. It is possible too that the attempt to settle Lombards was not the effect of the invitation but only failed attempt of fixing the situation caused by their lawless arrival

Małgorzata Skowronek, Średniowieczne opowieści biblijne. Paleja historyczna w tradycji bizantyńsko-słowiańskiej [Medieval Biblical Stories. Palaea Historica in the Byzantine-Slavic Tradition], Wydawnictwo Uniwersytetu Łódzkiego, Łódź 2017 [= Series Ceranea, 4], pp. 396.

Publication of English-language versions of the volumes of the yearly Studia Ceranea financed through contract no. 501/1/P-DUN/2017 from the funds of the Ministry of Science and Higher Education devoted to the promotion of scholarship

Relacje longobardzko-bizantyńskie od początków VI w. do upadku egzarchatu Rawenny (751 r.)

W I połowie VI w., kiedy Longobardowie osiedlili się na terenach Panonii, zazwyczaj występowali w roli sojuszników cesarstwa bizantyńskiego. Po dokonaniu przez Longobardów inwazji na Italię w 568/569 r. i osiedleniu się tam przez nich relacje przybrały jednak otwarcie wrogi charakter. Król Alboin szybko podbił północną część półwyspu a na południu wykrystalizowały się księstwa Spoleto i Benewentu. Longobardzka aktywność w Italii spotkała się z bardziej zdecydowaną odpowiedzią Bizancjum w czasach panowania Maurycjusza. Władca ten zreorganizował administrację bizantyńską na półwyspie, tworząc w 584 r. egzarchat Rawenny, a próbując poskromić Longobardów uciekał się początkowo do pomocy sojuszników frankijskich. Siły bizantyńskie podejmowały się też ograniczonych prób samodzielnych ofensyw. Konfrontacyjna polityka przynosiła jednak bizantyńskiej Italii zbyt duże szkody i w 598 r. zawarto pierwszy z serii rozejmów. Kolejny cesarz – Fokas, zmagając się z zagrożeniem sasanidzkim, prowadził w Italii pokojową politykę. Układ zawarty między cesarstwem a królem Agilulfem w 609 r. można zaś uznać za de facto uznanie podmiotowości longobardzkiego królestwa przez Konstantynopol. Wzajemne relacje w VII w. niewątpliwie straciły na intensywności, choć wrażenie to jest po części wynikiem spadku liczby przekazów źródłowych. Do istotnych wydarzeń, które miały miejsce w tym czasie, należą nieudana kampania egzarchy Eleuteriusza, podbój Ligurii przez Longobardów w latach 40., wyprawa przeciwko Benewentowi podjęta przez cesarza Konstansa II w 663 r. i potencjalny układ zawarty ok. 680 r. Longobardzki napór na egzarchat uległ wznowieniu w trakcie rządów króla Liutpranda (712–744). Do zajęcia Rawenny i likwidacji egzarchatu doszło jednak dopiero w 751 r. za panowania króla Aistulfa

The Image of Muhammad in Riccoldo da Monte di Croce’s "Contra legem Sarracenorum"

Contra legem Sarracenorum written by the Dominican Riccoldo da Monte di Croce was considered one of the most influential medieval Christian anti-Islamic polemics. The treatise was devoted to criticism of the Quran, which was also reflected in the way Muhammad was presented there. It offers an image of the prophet that is rather blurry considering that the author’s focus is on the contents and the form of the book. Despite that, at least three distinct categories regarding the image of Muhammad can be distinguished in Contra legem Sarracenorum. He was portrayed, first and foremost, as a heresiarch, as a false prophet (most of the information about the prophet included in this work is used to support that view), and simply as an evil man. The image of Muhammad outlined by Riccoldo is largely dependent on the contents of the Mozarabic polemic treatise Liber denudationis, which the author used profusely. Muhammad is present in Contra legem Sarracenorum mainly in an indirect way as the creator of the teachings contained in the Quran. Generally speaking, in this specific aspect, one cannot speak of constructing an image of the prophet because in these fragments, the polemic conducted by Riccodlo focuses not so much on the person of Muhammad as on the contents of the book ascribed to him, in isolation from the creator

Film thickness and friction of ZDDP tribofilms

Tribofilm formation by several zinc dialkyl- and diaryldithiophosphate (ZDDP) solutions in thin film rolling-sliding conditions has been investigated. A primary, a secondary alkyl and a mixed alkyl ZDDP show similar rates of film formation and generate films typically 150 nm thick. Another secondary ZDDP forms a tribofilm much faster and the film is partially lost after extended rubbing. An aryl ZDDP forms a tribofilm much more slowly. The films all have a pad-like structure, characterised by flat pad regions separated by deep valleys. Three different techniques have been used to analyse the thickness and morphology of the tribofilms: spacer layer imaging (SLIM), scanning white light interferometry (SWLI) of the gold-coated film and contact mode atomic force microscopy (AFM). The SLIM method measures considerably thicker films than the other two techniques, probably because of lack of full conformity of a glass disc loaded against the rough tribofilm. No evidence of a highly viscous layer on top of the solid tribofilm is seen. SWLI and contact mode AFM measure similar film thicknesses. The importance of coating the tribofilm with a reflective layer prior to using SWLI is confirmed. As noted in previous work, the formation of a ZDDP tribofilm is accompanied by a marked shift in the Stribeck friction curve towards higher entrainment speed. For a given ZDDP this shift is found to correlate with the measured tribofilm roughness, proving that it results from the influence of this roughness on fluid entrainment in the inlet

What does it mean to recover from a gambling disorder? Perspectives of gambling help service users

Background: There is no consensus on how to best define recovery in gambling disorder. This minimizes clinicians’ abilities to apply optimal treatment goals and contributes to inconsistency in the use of outcome variables to evaluate interventions. Current understanding of recovery is largely based on professional opinion and theoretical models of gambling disorder. This study aimed to examine core features of recovery identified by service users with lived experiences. Methods: Thematic analysis was applied to qualitative data from 32 face-to-face interviews. Interviewees were at various stages of help-seeking for gambling problems mostly related to electronic gaming machines via self-exclusion and/or specialized gambling counseling. Results: Recovery was perceived by the participants as a continuous process that encompasses periods of improvement and decline. Several key themes of recovery emerged; participants highlighted the importance of developing insight into the psychological and environmental processes that contribute to their gambling problem. Insight helped participants feel empowered to successfully manage their gambling urges and behavior. Recovery extended to building a meaningful life beyond gambling, which involved engagement in alternative activities and fostering strong social relationships. It included stabilization of personal finances and achieving general psychological health and wellbeing. Conclusions: Findings challenge acute symptom-focused models of recovery by broadening the definitional boundaries to include sustained improvements across multiple psychosocial dimensions. Greater emphasis should be given to service user-defined elements of recovery in treatment and research. The long-term perspective of the recovery process has implications for extending standard follow-up assessment intervals in gambling treatment studies.This study was partly funded by a deed of gift from ClubsNSW. The investigators conducted the research with no input from ClubsNSW in the design or methodology of the study. ClubsNSW imposed no constraints on publishing the results of the study. The authors alone are responsible for the content and writing of this article. This work was also supported by University postgraduate research funding awarded to Dylan Pickering, and an Australian Research Council Discovery Early Career Research Award [DE1060100459] awarded to Dr. Sally Gainsbury

A qualitative exploration of problem gambling trajectories during and after self-exclusion

Abstract (max 200 words) Although existing research has focused on reasons for self-excluding, and overall program effectiveness, there is a lack of empirical evidence on gambling behaviour during and after self-exclusion. To address this gap, the aim of this research was to explore problem gambling trajectories during and after self-exclusion. The life course perspective was used as an organizing framework for characterizing patterns in gambling behaviour, identifying points of change, and determining potential factors contributing to gambling change over time. Audio-recorded semi-structured interviews were conducted with 20 people enrolled in a multi-venue self-exclusion program. Thematic analysis was used to analyze the data. Three unique gambling trajectories were identified during self-exclusion: complete abstinence from all gambling, compliance with the agreement but gambled in non-banned venues, and non-compliance. Timing of initial violations varied with some returning to gambling almost immediately after entering self-exclusion, others maintained abstinence for a couple of months, and a handful returned to gambling nearing the end of their gaming ban. After the conclusion of the self-exclusion participants either renewed their self-exclusion immediately, returned to gambling briefly and then renewed their agreement, returned to gambling without foreseeably planning to renew their self-exclusion ban, or maintained abstinence without renewing self-exclusion. Limitations and future research will be discussed. Clear statement of the implications (i.e., the “so what”; max. 50 words) Previous research has shown that people enrolled in self-exclusion programs benefit from additional supports such as counselling and follow-ups from venue staff. The present research can be used to implement additional supports at targeted points during self-exclusion before problem gamblers are most likely to violate their gaming ban therefore increasing program compliance

The image of the Lombards in "Liber Pontificalis". From the invasion of Italy till the fall of their Kingdom (568/569–774)

The article concerns the image of the Lombards in Liber Pontificalis, the chronicle of papal pontificates, which represented point of view of popes and their environment. In biographies of popes from the end of 6th century the Lombards appeared quite often as invaders plundering Italy however, due to generally laconic and reporting character of those vitae, information which concerned the Lombards was short and deprived of clear rhetorical features. In biographies from 7th century the Lombards were absent. The Lombards became the object of biographers’ interest in 8th century along with resuming Lombard military pressure. Biographies from that period were literary expanded and focused on Lombard rulers. The image of the kings was quite diverse in them though all were treated as danger for the Apostolic See. In the case of king Liutprand, positive elements was noticed as well. The image of Ratchis is similar. Aiustlf was described in extreme negative way because he attempted to conquer Rome. The median of the images of Liutprand and Aisutlf is the image of king Desiderius. Right is the claim, that the negative image of the Lombards in that period was attached to the lack of earlier intensive contact between them and papacy, which escalated in Rome the feeling of unfamiliarity and memory of the danger they were in 6th century. It seems however that the crucial factor, influencing on the image of the Lombards in Liber Pontificalis, was just the necessity to present the popes in the most positive way, what was done at the cost of the Lombards.Artykuł dotyczy obrazu Longobardów w Liber Pontificalis, kronice pontyfikatów papieży, reprezentującej punkt widzenia biskupów Rzymu i ich otoczenia. W biogramach papieży z końca VI w. Longobardowie pojawiają się stosunkowo często, jako najeźdźcy pustoszący Italię. Jednak ze względu na ogólnie lakoniczny i sprawozdawczy charakter tych vitae informacje dotyczące ludu są krótkie i pozbawione wyraźnych cech retorycznych. W biogramach z VII w. Longobardowie są nieobecni. Związane jest to najprawdopodobniej z faktem, że w tym czasie przestali stanowić dla Rzymu bezpośrednie zagrożenie. Longobardowie stali się ponownie przedmiotem zainteresowania autorów biogramów papieży w VIII w., wraz ze wznowieniem longobardzkiej presji militarnej. Biogramy z tego okresu są bardzo rozbudowane literacko i skupiają się głównie na poczynaniach władców longobardzkich. Obraz królów jest dość zróżnicowany, choć wszyscy traktowani są jako zagrożenie dla Stolicy Apostolskiej. W przypadku Liutpranda odnotowywane są jednak także elementy, które stawiają go w pozytywnym świetle. Podobny jest wizerunek Ratchisa. W skrajnie negatywny sposób przedstawiony został Aistulf, dążący otwarcie do zdobycia Rzymu. Wypadkową wizerunków Liutpranda i Aistulfa jest natomiast obraz ostatniego longobardzkiego króla – Dezyderiusza. Słuszne jest twierdzenie, że za negatywny obraz Longobardów w tym okresie odpowiada w pewnym stopniu brak wcześniejszych intensywnych kontaktów między nimi a papiestwem, potęgujący poczucie obcości i pamięć o zagrożeniu, jakie stwarzali pod koniec VI w. Wydaje się jednak, że kluczowym czynnikiem, wpływającym na wizerunek Longobardów w Liber Pontificalis, była po prostu konieczność przedstawienia w jak najlepszym świetle kolejnych papieży i podejmowanych przez nich działań, co odbywało się kosztem stanowiących zagrożenie Longobardów