Structural Basis for the Anomalously Low Spontaneous Polarisation Values of the Polar Phase of Sr1-xCaxTiO3 (x=0.02, 0.04): Evidence for a Ferrielectric Ordering

Full pattern Le-Bail refinement using x-ray powder diffraction profiles of Sr1-xCaxTiO3 for x=0.02, 0.04 in the temperature range 12 to 300 K reveals anomalies in the unit cell parameters at 170, 225 K due to an antiferrodistortive (cubic to tetragonal I4/mcm) phase transition and at ~32, ~34 K due to a transition to a polar phase (tetragonal I4/mcm to orthorhombic Ic2m), respectively. The lower transition temperatures obtained by us are in excellent agreement with those reported on the basis of the dielectric studies by Bednorz and Muller, [10] who attributed these to ferroelectric transition. Rietveld analysis of the diffraction profiles of the polar phase reveals off-centre displacements of both Sr2+/Ca2+ and Ti4+ ions in the X-Y plane along pseudocubic directions, in agreement with the experimentally reported direction of easy polarization by Bednorz and Muller, but the resulting dipole moments are shown to be ferrielectrically coupled in the neighbouring (001) planes along the [001] direction leading to anomalously low values of the spontaneous polarization at 12K.Comment: 5 pages, 4 figures and 1 tabl

City Managers, Career Incentives, and Service Delivery Decisions: The Effects of Managerial Ambition on Interlocal Cooperation Choices

City Managers are believed to play a particularly influential role in brokering cooperative service deals on behalf of their jurisdiction (Krueger and McGuire, 2005; Thurmaier and Wood, 2002; Morgan and Hirlinger, 1991), however, their motivations for doing so are not well understood. One argument, drawn from theories of bureaucratic entrepreneurship and ambition theory suggests that cities with managers who want to move up in their career will engage in more interlocal service delivery as means of capturing economic efficiencies, which helps to build their record of career achievements. An alternative theoretical argument suggests that more altruistic motives including a desire for increased social equity, and valuing the common good of the region guide, are responsible for guiding city managers decisions for interlocal cooperation. We test these competing hypotheses using survey data from 134 city managers of large municipalities, and finance data from the Historical Database of Individual Local Government Finances. We find strong support for the first theory, and no support for the alternative argument. Managerial ambition has important consequences for the rate at which cities engage in interlocal service cooperation, but local fiscal capacity also shapes these decisions. Moreover, managerial ambition has complex effects; the desire of the city manager to move onto a larger city in the near future increases the rate at which a city sells services to other local governments, but managerial career ambition decreases the rate at which cities are willing to buy services from another jurisdiction

Stereotypies in adults: a systematic review

Stereotypies are abnormal involuntary non-goal-directed movement patterns or vocalisations which repeat continuously in the same fashion over a period of time and on multiple occasions and are typically distractible. Stereotypies are common in both children and adults, but they are extensively reviewed only in children. There are very few studies, mainly in the form of case reports and case series, focusing on stereotypies occurring in adults as part of different neurological disorders. In adults, stereotypies can be both physiological and pathological. Common physiological stereotypies in adults are leg shaking, face touching, playing with pens or hair, nail biting, hand tapping, foot tapping, and body rocking. Pathological stereotypies in adults are associated with a variety of neuropsychiatric conditions like neurodegenerative disorders, viral encephalitis, autoimmune encephalitis, stroke, psychiatric illness, and drug use. In this review, we focus on the various causes of stereotypic movements in adults, and their pathophysiology, clinical manifestations, and treatment

Functional Movement Disorders in Elderly

Background: Functional movement disorders (FMDs) have been rarely described in the elderly population. Methods: This is a retrospective chart review of elderly patients with FMDs (onset >60 years) attending the movement disorders clinic at a tertiary care teaching institute in India. Results: Out of 117 patients diagnosed with FMD at our center, 18 patients had an onset after the age of 60 years. The male-to-female ratio was 10:8 and the duration of symptoms ranged from 1 day to 5 years. Social (10/18) and physical factors (5/18) with an evident temporal relationship with the onset of FMD were identified in 15 out of 18 patients. Six of them had a past history of depression, anxiety, or other psychiatric illnesses. The tremor was the most frequent phenomenology seen in 11 (61.1%) patients, followed by dystonia in seven (38.8%), choreoballism and tics in two each, and hemifacial spasm and functional gait in one each. Seven patients had more than one phenotype. Discussion: Tremor was the most frequent movement disorder seen in our patients with FMD. Surprisingly, tics (n = 2) and choreoballistic (n = 2) movements were also found in our patients with FMD, which has not been reported previously in an elderly population. Both physical and social factors were identified preceding the development of FMDs in majority of our patients

Mechanical Behaviour of Polypropylene And Human Hair Fibres And Polypropylene Reinforced Polymeric Composites

Bio fibres have recently become eye-catching to researchers, engineers and scientist as an alternative reinforcement for FRP (fibre reinforced polymer) composite. Due to their low cost, fairly good mechanical properties, high aspect strength .Three to four ton of human hair fibre wasted in India annually .These fibre pose an environmental challenge In order to find commercial application the wasted human hair fibre mixed with polypropylene. Polypropylene based composite are prepared using hair fibre obtained from human hair. Human hair fibres are mixed into polypropylene (PP) at 3,5,10 and 15 % by wt. using two roll mills. The composite are compression moulded at specific time and temperature. Polypropylene and hair fibre polymer reinforced composite have better flexural and impact strength than PP (Polypropylene) and lower the tensile strength of polypropylene and hair fibre polymer reinforced composite than (PP) polypropylene