Rollover Preventive Force Synthesis at Active Suspensions in a Vehicle Performing a Severe Maneuver with Wheels Lifted off

Among the intelligent safety technologies for road vehicles, active suspensions controlled by embedded computing elements for preventing rollover have received a lot of attention. The existing models for synthesizing and allocating forces in such suspensions are conservatively based on the constraint that no wheels lift off the ground. However, in practice, smart/active suspensions are more necessary in the situation where the wheels have just lifted off the ground. The difficulty in computing control in the last situation is that the problem requires satisfying disjunctive constraints on the dynamics. To the authors',knowledge, no efficient solution method is available for the simulation of dynamics with disjunctive constraints and thus hardware realizable and accurate force allocation in an active suspension tends to be a difficulty. In this work we give an algorithm for and simulate numerical solutions of the force allocation problem as an optimal control problem constrained by dynamics with disjunctive constraints. In particular we study the allocation and synthesis of time-dependent active suspension forces in terms of sensor output data in order to stabilize the roll motion of the road vehicle. An equivalent constraint in the form of a convex combination (hull) is proposed to satisfy the disjunctive constraints. The validated numerical simulations show that it is possible to allocate and synthesize control forces at the active suspensions from sensor output data such that the forces stabilize the roll moment of the vehicle with its wheels just lifted off the ground during arbitrary fish-hook maneuvers

Frequency dependent superfluid stiffness in the pseudogap regime in strongly disordered NbN thin films

We measure the frequency dependence of the complex ac conductivity of NbN films with different levels of disorder in frequency range 0.4-20 GHz. Films with low disorder exhibit a narrow dynamic fluctuation regime above T_c as expected for a conventional superconductor. However, for strongly disordered samples, the fluctuation regime extends well above T_c, with a strongly frequency-dependent superfluid stiffness which disappears only at a temperature T* close to the pseudogap temperature obtained from scanning tunneling measurements. Such a finite-frequency response is associated to a marked slowing down of the superconducting fluctuations already below T*. The corresponding large length-scale fluctuations suggest a scenario of thermal phase fluctuations between superconducting domains in a strongly disordered s-wave superconductor.Comment: pdf file: 18 pages including figure

Promoter polymorphism of IL-8 gene and IL-8 production in pulmonary tuberculosis

Interleukin-8 (IL-8) is a chemokine which functions as a potent chemo attractant for the recruitment of leucocytes to the inflammatory sites. A polymorphism in position –251 in the promoter region of the IL-8 gene has been shown to be associated with altered IL-8 production. IL-8-251A promoter polymorphism was studied in 127 pulmonary tuberculosis (PTB) patients and 124 normal healthy subjects (NHS). IL-8 gene variants were correlated with IL-8 levels from peripheral blood mononuclear cells stimulated with phytohaemagglutinin, culture filtrate antigen (CFA) of Mycobacterium tuberculosis and live M. tuberculosis. No difference was observed in the variant genotype frequencies of IL-8 gene and IL-8 levels between NHS and PTB patients. NHS positive for TT genotype showed a higher spontaneous IL-8 production than AA genotype (P = 0.05). Similarly, PTB patients with TT genotype showed significantly higher IL-8 production to CFA (P = 0.009) and live M. tuberculosis (P = 0.022), compared to patients with AA genotype. The study suggests that the variant genotypes of –251 promoter polymorphism of the IL-8 gene are not associated with susceptibility to PTB. Probably, TT genotype may be associated with higher IL-8 production and increased leucocyte accumulation and inflammation at the site of M. tuberculosis infection

Assessment of nicotine dependence in subjects with vascular dementia

Background: Nicotine dependence is an important public health issue. Nicotine dependence is a risk factor for vascular diseases like myocardial infarction and vascular dementia. The rate of nicotine dependence in Indian subjects with vascular dementia is not known. Hence we decided to assess nicotine dependence in subjects with vascular dementia.Methods: Nicotine dependence in subjects with vascular dementia was assessed among subjects presenting to memory clinic of a tertiary care hospital over a period of 16 months. Data regarding sociodemographic profile and severity of nicotine dependence as per Fagerstrom nicotine dependence scale for smoking and smokeless tobacco was analysed using SPSS version 17.Results: Our study shows that in 159 subjects with vascular dementia continuing nicotine dependence was seen in nearly 12% of the subjects. Though the rates are less than the population prevalence for India, it is still relevant as nicotine is not just a risk factor for development of vascular dementia but severe nicotine dependence and longer duration of nicotine use were found to be poor prognostic factors associated with severe dementia. Further as all subjects continued to be nicotine dependent despite having been advised to quit tobacco, suggesting the need for a more comprehensive tobacco cessation intervention be offered to subjects with vascular dementia to improve outcomes.Conclusion: In subjects with vascular dementia continuing nicotine dependence is an important risk factor which must be addressed.  

Unicornuate uterus with rudimentary horn, gynaecological and reproductive outcome

Congenital malformations of the female genital tract occur in about 8-10% of all women. The unicornuate uterus is a result of partial or complete agenesis of one of the paired Mullerian ducts. It could be a true unicornuate uterus or along with a rudimentary horn, which may be functional. When the rudimentary functional horn is non-communicating, most patients become symptomatic after menarche or present with pregnancy related problems. Three clinical presentations of unicornuate uterus with non-communicating rudimentary horn encountered in last one year are described. The first case was of unruptured rudimentary horn pregnancy of 11-12 weeks. Second case had rudimentary horn removed as an adolescent due to intractable pain, but later main uterus harboured an uneventful pregnancy. Case three had two early abortions, followed by term caesarean section for fetal distress. With advent of ultrasonography and other imaging techniques, the diagnosis and management of unicornuate uterus and its variations is possible. The functional rudimentary horn if symptomatic must be removed along with ipsilateral tube. A unicornuate uterus is associated with obstetric problems and such women should be considered as high risk pregnancy

A Grid-connected Hybrid Renewable Energy System Using High-frequency Multi-winding Transformer and Phase Shift Modulation Technique

This paper presents a topology of multi-port phase-shift converter for integration of a PV system, a wind-turbine generator and a battery to supply a grid-connected domestic load. The main advantage of the topology is using a multi-winding high-frequency transformer to couple the input and outputs of the system. This simplifies the power flow control and provides isolation between the converter ports. Detailed operation of the proposed topology and the control system analysis are discussed. A numerical simulation of the proposed system is carried out to confirm the system operation and control technique

High-K dielectric sulfur-selenium alloys.

Upcoming advancements in flexible technology require mechanically compliant dielectric materials. Current dielectrics have either high dielectric constant, K (e.g., metal oxides) or good flexibility (e.g., polymers). Here, we achieve a golden mean of these properties and obtain a lightweight, viscoelastic, high-K dielectric material by combining two nonpolar, brittle constituents, namely, sulfur (S) and selenium (Se). This S-Se alloy retains polymer-like mechanical flexibility along with a dielectric strength (40 kV/mm) and a high dielectric constant (K = 74 at 1 MHz) similar to those of established metal oxides. Our theoretical model suggests that the principal reason is the strong dipole moment generated due to the unique structural orientation between S and Se atoms. The S-Se alloys can bridge the chasm between mechanically soft and high-K dielectric materials toward several flexible device applications