1,322 research outputs found
Discomfort of seated persons exposed to low frequency lateral and roll motion
No full textPassengers of land transport are exposed to horizontal and rotational oscillations at frequencies less than 1 Hz which may cause vibration discomfort and motion sickness. Previous knowledge of human responses to motion is insufficient for predicting the discomfort caused by low frequencies. The objective of this thesis is to improve understanding of subjective responses to lateral and roll oscillation (presented in isolation and in combination) at frequencies less than 1 Hz in order to establish a predictive model of comfort.The first of five experiments tested the predictions of a conceptual model of motion sickness. Illness ratings were obtained over a 30-minute exposure to 0.2 Hz fully roll-compensated lateral oscillation where the point of full roll-compensation was either at the seat surface (i.e. ‘seat compensation’) or at head height (i.e. ‘head compensation’). Median illness ratings were greater during ‘head compensation’, showing some support for the motion sickness model, but differences were not statistically significant. Age, stature and body weight had no effect on illness ratings, but Asians were more than three-times as likely to experience ‘mild nausea’ than Europeans. It is concluded that differences in the position of full roll-compensation in transport vehicles are less important for motion sickness than inherent differences in passenger populations.The next four experiments used the method of magnitude estimation to determine the vibration discomfort caused by lateral oscillation, roll oscillation, and fully roll-compensated lateral oscillation with a variety of seating configurations. In the second experiment, lateral acceleration between 0.2 and 1.0 Hz caused less discomfort when sitting with a backrest than when sitting without a backrest on both a rigid seat and on a cushioned train seat; contrary to the predictions of current standards. In the third experiment, 0.25 to 0.4 Hz lateral acceleration in the plane of the seat caused similar discomfort regardless of whether the acceleration was due to lateral oscillation or roll oscillation through the gravitational vector, but above 0.4 Hz, discomfort from the roll was far greater. At frequencies less than 0.5 Hz, fully compensating the lateral acceleration with roll improved comfort compared to uncompensated lateral acceleration, but at greater frequencies, roll-compensation worsened comfort and caused discomfort similar to pure roll oscillation at 1 Hz.The fourth and fifth experiments examined differences in discomfort caused by the rigidity of the seat pan and the height of the backrest. In the fourth experiment, discomfort was greater on a soft foam seat than on a rigid seat during lateral oscillation below 0.63 Hz, during roll oscillation below 0.5 Hz and during fully roll-compensated lateral oscillation between 0.315 and 0.5 Hz. In the fifth experiment, discomfort was greater without a backrest than with a short backrest for lateral oscillation between 0.315 and 0.5 Hz. Contrary to current standards, discomfort was also greater without a backrest than with a high backrest for lateral oscillation below 1 Hz and for roll oscillation below 0.5 Hz. In addition, sitting with a backrest was beneficial for comfort with fully roll-compensated lateral oscillation between 0.4 and 0.63 Hz.The results of the five experiments were collated to provide recommendations for the improvement of current vibration standards. On the basis of experiment 1, a new multiplying factor for the prediction of vomiting incidence in an unadapted group of male Asian adults is offered. On the basis of the four discomfort experiments, modifications to current frequency weightings for lateral acceleration and roll acceleration are offered so as to extend the prediction to frequencies less than 0.5 Hz. Guidance for the prediction of discomfort with fully roll-compensated lateral oscillation is also provided. The thesis is concluded with recommendations for future research
Synthesis and properties of complexes of vanadium(V) oxide trichloride with nitrogen- and oxygen-donor ligands
No full textIntensely coloured, extremely moisture sensitive complexes [VOCl3(L)] (L = pyridine, quinoline, Ph3PO, Ph3AsO, pyridine N-oxide), [VOCl3(L)(2)] (L=pyridine, Me3PO, pyridine N-oxide), [VOCl3(L-L)] [L-L = 2,2'-bipyridyl, 1,10-phenanthroline, Ph2P(O)CH2P(O)Ph-2, MeOCH2CH2OMe, 15-crown-5 or Me2NCH2CH2NMe2] and [Cl3OV(mu-L-L)VOCl3] [L-L=18crown-6 or Ph2P(O)CH2P(O)Ph-2] have been prepared from VOCl3 and the appropriate ligands in dichloromethane solution. These constitute the first extended series of complexes of vanadium(V) with neutral donor ligands. They have been fully characterised by analysis, IR, UV/Visible and multinuclear (H-1, P-31, V-51) NMR spectroscopy, and their solution behaviour probed as a function of temperature using 51V NMR spectroscopy. Reducing ligands including phosphanes, arsanes, thio- and selenoethers immediately reduce VOC13 to give V-IV or V-III species. Oxygen atom transfer reactions of some of the complexes with Ph3P, Ph3As, Me2Se and Bu2S, leading to the corresponding ligand oxides are also described
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Letter from C.D. Darlington to Janaki Ammal, 18 January, 1960
No full textLetter from C.D. Darlington to Janaki Ammal. Darlington requests information on criminal castes, which he ultimately used for a section of his controversial trilogy of books, Genetics and Man (1953), The Evolution of Man and Society (1969) and the Little Universe of Man (1978). These books have subsequently received criticism for biological determinism, because of the unsubstantiated emphasis that they placed on biological causes of social behaviour.
Author: C.D. Darlington
Date: 18 January, 1960
Source: Bodleian Library Archives, Folder: MS DARLINGTON/J114
(C) Reproduced with Permission of C.D. Darlington's family</p
Studies on chromium(III) and vanadium(III) complexes with crown ether and crown thioether coordination - Synthesis, properties and structural systematics
No full textA series of six-coordinate chloro Cr-III and V-III complexes involving crown ether, crown thioether and mixed ether/thioether crowns, [MCl3(crown)] (M = Cr or V, crown = 12-crown-4, 15-crown-5,18-crown-6, [12]aneS(4), [15]aneS(5), [9]aneS(2)O, [15]aneS(2)O(3), [18]aneS(3)O(3)) has been prepared by the reaction of [MCl3(thf)(3)] with rigorously dried crown in anhydrous CH2Cl2. In the presence of small amounts of water the monoaquo species [MCl3(H2O)(15-crown-5)] and [MCl3(H2O)(18-crown-6)] are obtained. The products have been characterised by IR and UV/Visible spectroscopy, microanalyses and for [CrCl3(H2O)(18-crown-6)], [VCl3(H2O)(15-crown-5)] and [CrCl3([15]aneS(5))], by X-ray crystallography. The unexpected affinity of specifically the 15-crown-5 and 18-crown-6 complexes to pick up H2O is rationalised in terms of the strain within the two adjacent five-membered chelate rings in the anhydrous (kappa(3)-coordinated) species, and a wider survey of the structures reported for six-coordinate M-III crown complexes (M = Sc - Cr) with RECH2CH2ER (E = 0 or S) reveals that while the S-M-S angles in five-membered chelate rings are typically around 82 degrees, those involving O-M-O are very substantially more acute at around 75 degrees. Thus, the [MCl3 (kappa(3)-crown ether)] complexes are much less stable and can alleviate some of this significant ring strain by switching to kappa(2)-crown coordination with the H2O ligand completing the six coordination. In contrast, the crown thioether complexes have much less tendency to do this and hence appear to be more stable. Furthermore, using the structurally related (dimethylene linkages) mixed thia/oxa crowns to probe the M-O vs. M-S binding competitively, strongly indicates that the Cr-III and V-III preferentially coordinate to the thioether rather than the ether donor atoms, contrary to normal expectation based upon HSAB theory
A suitable girl : Daṇḍin and a meal on the banks of the Kāverī
No full textIn the sixth ucchvāsa of the Daśakumāracarita, Daṇḍin narrates a short story in which a young man coming from Kāñcī is in search for a bride. He finds the suitable girl in a town on the banks of the Kāverī; her beauty is a sign of auspiciousness, and she proves to be able to cook a full meal only with the aid of a limited amount of rice. As for the meal, the passage is extremely interesting from a documentary point of view, because it describes its preparation in full detail. As well known, Daṇḍin is a Pallava poet, who writes around 700 CE; Kāñcī was the Pallava capital at that time, and the full story appears to take place in Pallava territory. The author must know the recipes he is describing quite well. But, besides providing a pleasant short novel, he almost surely had other aims as well. Daṇḍin is always very precise in locating the adventures of his characters, who quite often are of dubious morality. It is most probable that this perfect wife, and the ‘pure’ meal proposed, are also to be read as a way to extol the virtuous women and the Brahmanic customs of the Pallava country, and thus of the Dravidian South
Change is in the Cards: Competition in the Canadian Debit Card Market
No full textAs new entrants arrive in Canada’s debit card market, rule changes are needed to ensure a level playing field, and to enhance the potential benefits of competition for consumers and merchants. In a study released today, the author assesses the implications of the rapidly changing debit payment landscape. Bergevin makes recommendations for action to ensure that consumers and merchants are protected and that the system can evolve to serve them even better.financial services, debit card market, VISA, MasterCard, Interac
Le prime coordinate giurisprudenziali sulla c.d. "opposizione alla perquisizione negativa"
No full textLa Corte di cassazione fornisce le prime coordinate interpretative sulla c.d. “opposizione alla perquisizione negativa”. La disamina della sentenza pone all’interprete questioni piuttosto serie, che l’autore si propone di esaminare, riflettendo sull’oggetto del sindacato giurisdizionale condotto dal g.i.p., sulla base documentale di quel giudizio, sulla esperibilità del ricorso per cassazione avverso l’ordinanza così adottata, nonché sull’applicabilità del rimedio alle c.d. “perquisizioni speciali”.The Italian Court of Cassation provides the first interpretative coordinates about the remedy so-called ‘Opposition to the negative search’. The judgement leads the jurist to reflect on serious issues, which the author proposes to explain, by examining the object of the judicial review conducted by the judge, the documentary basis of that judgement, the admissibility of the appeal to the Court of Cassation against the judge’s decision, as well as the applicability of the remedy to the so-called ‘special searches’
Lagging Behind: Productivity and the Good Fortune of Canadian Provinces
No full textThe good fortune of bountiful natural resources is not enough to ensure rising incomes for Canadians in the long term. Growing labour productivity is the most important determinant of future economic welfare and on that measure, Canada is falling behind its major trading partners. Increasing labour productivity does not mean workers working harder for less money, a common canard. It means more investment in one of three factors: 1) human capital (education or other learning); 2) physical capital (plants or other infrastructure); or 3) technology. Just as an individual’s income is in the long-run dependent on how productive he or she is, so too is that of the nation as a whole. If Canada fails to improve its productivity, the incomes of both individual Canadians and the nation as a whole will fall behind those of other developed countries.Economic Growth and innovation, Canadian provinces, labour productivity
What Does it Cost Society to Raise a Dollar of Tax Revenue? The Marginal Cost of Public Funds
No full textThe marginal cost of public funds measures the welfare loss a society incurs in raising an additional dollar of tax revenue. Tax increases distort economic decisions and erode tax bases because of tax avoidance and tax evasion by taxpayers. This Commentary uses econometric estimates of the effects of higher provincial tax rates on the provinces’ corporate income tax, personal income tax, and sales tax bases to calculate the marginal cost of public funds (MCF) for these taxes. The results indicate that the cost of increasing provincial tax revenues through a corporate tax rate increase is very high, and in some provinces, corporate tax rate reductions in 2006 would have increased the present value of the provincial government’s total tax revenues. The results also suggest that significant welfare gains would accrue from reducing provincial corporate income tax rates. As well, increasing provincial corporate and personal income tax rates can cause significant reductions in federal tax revenues because the federal and provincial governments levy taxes on the same tax bases. Finally, Canada’s system of the equalization grants might reduce the perceived MCF of recipient provinces.Fiscal and Tax Competitiveness, marginal cost of public funds (MCF)
Aboriginal Education in Quebec: A Benchmarking Exercise
No full textQuebec’s Aboriginal poverty is severe, and the large gap between Aboriginal and non-Aboriginal education levels is the most important factor in explaining it. In the report, the author examines the relationship between education levels and employment for Quebec Aboriginals. Comparing outcomes within the province’s Aboriginal identity groups to results for other Quebecers, and for Canadians overall, Richards finds that the province’s Aboriginal education outcomes rank below the Canadian average, which itself is disturbingly low. Richards makes six broad recommendations to address the crisis in Aboriginal education – in Quebec and the rest of Canada.The Education Papers, Canada, Quebec, Aboriginals, education, employment
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