Mapping the thermal distribution within a silica preform tube using regenerated fibre Bragg gratings

The temperature profile of the reaction zone inside the silica substrate tube during thermal heating with a H₂/O₂ flame under conditions identical to those used in the fabrication of optical fibre preforms using a modified chemical vapour deposition lathe has been characterised with ultra-high temperature stable regenerated optical fibre Bragg gratings. Experimental and theoretical results indicate a significant drop in temperature – up to several hundred degrees – across the tube wall from outside to inside. These results are in contradiction with the broadly accepted assumption that there is no significant thermal gradient across the tube itself. An array of regenerated gratings demonstrates that optical fibre grating based sensing can achieve distributed ultra-high temperature mapping and monitoring in harsh environments.     

State space finite element analysis for piezoelectric laminated curved beam with variable curvature

ABSTRACT

A six-variable state vector formulation for static deformation of the laminated curved beam bonded with piezoelectric actuators is deduced. The 2D numerical solution for the piezoelectric laminated curved beams (PLCB) is explored. Then the distributions of the electrical and mechanical fields along the beam thickness direction are investigated analytically. The static shape control is researched for a laminated half circular beam covered with piezoelectric actuators. Comparisons with the available results show the reliability of the proposed method. At the end a spiral laminated piezoelectric structure is analyzed and the parameter study is carried out using the presented method.     

Indoor ozone/human chemistry and ventilation strategies

This study aimed to better understand and quantify the influence of ventilation strategies on occupant‐related indoor air chemistry. The oxidation of human skin oil constituents was studied in a continuously ventilated climate chamber at two air exchange rates (1 h^?1 and 3 h^?1) and two initial ozone mixing ratios (30 and 60 ppb). Additional measurements were performed to investigate the effect of intermittent ventilation (“off” followed by “on”). Soiled t‐shirts were used to simulate the presence of occupants. A time‐of‐flight‐chemical ionization mass spectrometer (ToF‐CIMS) in positive mode using protonated water clusters was used to measure the oxygenated reaction products geranyl acetone, 6‐methyl‐5‐hepten‐2‐one (6‐MHO) and 4‐oxopentanal (4‐OPA). The measurement data were used in a series of mass balance models accounting for formation and removal processes. Reactions of ozone with squalene occurring on the surface of the t‐shirts are mass transport limited; ventilation rate has only a small effect on this surface chemistry. Ozone‐squalene reactions on the t‐shirts produced gas‐phase geranyl acetone, which was subsequently removed almost equally by ventilation and further reaction with ozone. About 70% of gas‐phase 6‐MHO was produced in surface reactions on the t‐shirts, the remainder in secondary gas‐phase reactions of ozone with geranyl acetone. 6‐MHO was primarily removed by ventilation, while further reaction with ozone was responsible for about a third of its removal. 4‐OPA was formed primarily on the surfaces of the shirts (~60%); gas‐phase reactions of ozone with geranyl acetone and 6‐MHO accounted for ~30% and ~10%, respectively. 4‐OPA was removed entirely by ventilation. The results from the intermittent ventilation scenarios showed delayed formation of the reaction products and lower product concentrations compared to continuous ventilation.     

An active-control trial of lamotrigine monotherapy for partial seizures

OBJECTIVE: We report the results of a double-blind, double-dummy, active-control study designed to evaluate the efficacy and safety of lamotrigine (LTG) administered as monotherapy to adult outpatients with partial seizures. BACKGROUND: The effectiveness of LTG as add-on therapy for partial seizures in adults has previously been established. METHODS: After an 8-week baseline during which patients continued their baseline antiepileptic drug (carbamazepine or phenytoin monotherapy), 156 patients were randomly assigned to receive increasing doses of LTG (target 250 mg b.i.d.) or valproic acid (VPA; target low dose of 500 mg b.i.d.) during the first 4 weeks of an 8-week transition period. Carbamazepine or phenytoin was withdrawn over the next 4 weeks; then patients entered a 12-week monotherapy period. Study drug treatment was discontinued in patients who met predetermined escape criteria for seizure worsening. RESULTS: More patients receiving LTG were successfully maintained on monotherapy compared with patients receiving VPA (56% versus 20%; p < 0.001). The time to meet the escape criteria was also significantly longer in LTG-treated patients (median = 168 days) than in VPA-treated patients (median = 57 days; p = 0.001). The incidence of adverse events during the monotherapy period was lower than during the transition period. Four LTG patients and five VPA patients reported serious adverse events. Two of those patients experienced a rash that led to withdrawal soon after adding LTG to carbamazepine. CONCLUSIONS: We conclude that LTG is effective and well tolerated when administered as monotherapy in adult patients with partial seizures.     

A structural equation modeling approach to the multiple memory systems question.

Used linear structural equation modeling to test 2 models of declarative memory. A unitary model was compared with the semantic-episodic theory proposed by E. Tulving (e.g., 1972, 1983). The data consisted of performance scores of 300 Ss on 14 cognitive tests. The results of 2 sets of analyses suggest rejection of the unitary model but not the 2-factor model. Moreover, nested comparisons of the models revealed that the 2-factor model provided a significantly better fit to data than did the unitary model. Results support a division of declarative memory into memory for episodic information and memory for facts. This finding is discussed in terms of (1) different underlying memory systems mediating performance on semantic and episodic tests and (2) differences in the retrieval strategies that are required for accessing semantic and episodic information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Classification of CSF samples from normal and post-partum psychotic women using chromatographic profiles with bilinear projections: a multivariate approach

This paper demonstrates how chromatographic profiles of cerebrospinal fluid (CSF) have been subjected to multivariate data analysis to discriminate between CSF samples from women with post-partum psychosis and those from healthy women. Instead of peak-heights or areas, digitally defined chromatographic profiles were examined using principal component analysis (PCA). In accordance with the diagnosis, we have found a complex profile pattern of at least ten composite peaks that discriminates between these groups. Two of these peaks were for the discrimination particularly clearly between the two groups. We speculate that these findings can be useful in the diagnosis of post-partum psychosis, increasing diagnostic precision and having both clinical and prognostic implications.     

Evaluation of quality of life and symptoms after translabyrinthine acoustic neuroma surgery

OBJECTIVE: This study aimed to describe the consequences of acoustic neuroma surgery in terms of symptoms and quality of life. STUDY DESIGN: This study was a retrospective case review. SETTING: The surgery was conducted in Uppsala, Sweden. PATIENTS: A consecutive sample of acoustic neuroma patients operated on between 1988 and 1994. INTERVENTION: All patients had been operated on with the translabyrinthine technique. MAIN OUTCOME MEASURES: A questionnaire was constructed including questions about the surgery and symptoms. The House and Brackmann scale was used for grading facial function and the Brackmann and Bars scale was used for self-assessment of facial function. RESULTS: Follow-up data were collected by a postal questionnaire sent out and returned by 141 patients, which yielded a 90% response rate. Normal to moderately impaired facial function (House I-III) was evident in 85.2% of patients, although residual facial problems were reported. Most considered hearing to be worse after surgery (80%), and tinnitus was found in 60% of the sample. Balance problems (45%), dizziness (19%), and headache/pain (22%) were also reported. Work ability was affected in 23%, and 37% reported a continued need for medical consultations, mainly because of facial problems and pain. Most (89%) were pleased with the preoperative information. CONCLUSIONS: This study showed that few patients with acoustic neuroma had experienced negative social consequences after surgery. Although not linked to the operation, residual symptoms were reported that may necessitate further rehabilitation.     

The additive/antistat interaction in polypropylene

Analytical and performance data demonstrate chemical interactions between glycerol esters and various other additives, primarily acid neutralizers. This phenomenon is pronounced when the additive is a strong base, like synthetic hydrotalcite, or a metal carboxylate. The performance of lactate neutralizers is compared to stearates and metal bases. Chemical reactions are proposed based on the analytical tests performed.     

A cluster analysis of energy-consuming activities in everyday life

ABSTRACT

Flexible consumption in the household sector concerns individuals’ daily choices and the routines that develop in their households. Targeting household-level energy consumption therefore requires an understanding of energy consumption in relation to individual household members’ activity patterns. Individual time-diaries reveal when, for how long and where energy-related activities occur, permitting discussions of the temporal flexibility of these activities. Using multiple time-diaries (n?=?6477) from a population reveals differences in activity patterns in larger groups and permits recorded activities to be clustered. Few explorative studies perform cluster analyses of energy-consuming activities in order to examine when and for how long these activities occur. When clustering is done, it is usually based on socio-economic factors, and not on the activities performed in sequence. This paper reports a time-geographically inspired cluster analysis based on when and for how long some activities requiring electricity are performed in the home by individuals in a population. The presented cluster analysis based on activities gives a new perspective to the discussion of flexible users and provides a basis for deeper analyses, for example, of whether activities are moveable in time for individuals, complementing cluster analysis based on other variables.