Conducting polyaniline decorated in-situ poled Ferrite nanorod-PVDF based nanocomposite as piezoelectric energy harvester

PVDF-metal oxide based piezo-nanocomposite is an promising substitute of flexible nanogenerator. Herein, a ternary nanocomposite system Zinc Ferrite nanorod/Polyvinylidenefluoride (PVDF)/Polyaniline (PANI) nanochains was presented as alternative energy harvesting material. The inherent problem of low short-circuit current and high internal resistance of the nanocomposite was minimised by introducing a third phase cost-effective conducting supplementary filler, PANI nanochain.PANI assist to overcome the local dielectric dissimilarity by easy formation of conduction pathways via delocalization of pi-electrons present in the benzene ring and reduce the internal resistance of composite. Besides, it serves the role of dispersing agent by floating nanofillers throughout the volume and improves the homogeneity of filler distribution. Additionally, PANI reinforces composite with respect to stress accumulation and modulates the release behaviour by entangling with nanofillers by means of Van Der Waals force and helps to stabilize the polar PVDF. This lead to an improvement in electro-mechanical response and piezo-response behaviour of nanocomposite. The nanocomposite exhibits a similar to 42 V ac open circuit voltage and short circuit current density similar to 0.85 mu A/cm(2) with an overall increase in power density 35% compare to its binary metal-oxide/PVDF nanocomposite counterpart in response to single finger tapping and releasing. The generated power was utilized to illuminate twenty six number of red LEDs without any external energy storage unit. Also, the nanocomposite could charge up a commercial capacitor (10 mu F) within 115 s which can be used for alternative powersource in self-powered devices and sensors. (C) 2019 Published by Elsevier B.V

Flexible piezoelectric energy harvesters using different architectures of ferrite based nanocomposites

Electroactive phase transition in polyvinylidene fluoride (PVDF) can be economically achieved readily by addition of nanofillers. In this work, we have demonstrated the influence of rational design and structural control of nanofillers on nucleation and stabilization of an electroactive polymorph in PVDF. Different architectures of zinc ferrite (ZF) i.e. nearly spherical, nearly cubic, and rod-like were synthesized and further introduced in PVDF as a nucleating agent with different filler to polymer ratios. A comparative study of the dielectric and ferroelectric properties and energy harvesting performance of the corresponding nanocomposite was performed to obtain the best architecture based composite. It has been observed that one dimensional nanofillers are more favorable for polar phase transformation and stabilization with incorporation of a lower fraction of fillers. Thus, they exhibited maximum electrical performance (an energy storage density of 7.68 mJ cm(-3) with an energy discharge efficiency of similar to 77%, and an output piezoresponse of similar to 39.10 V with a power density of 2.96 mu W mm(-3)). This may be due to the preferred ` in-plane' orientation of the nanorod structure in the polymer matrix which helps to accumulate the entire short chain all-trans (TTTT) conformation and form an extended all-trans conformation corresponding to an electroactive ss-polymorph. This study may open a new strategy to design and fabricate ferrite-PVDF based electroactive nanocomposites with desired shapes for high performance energy storage and harvesting application

Duodeno-jejunal Atresia with Apple-peel Appearance of the Remaining Ileum: A Rare Association

Intestinal atresia is a common cause of neonatal intestinal obstruction. We present a rare case of duodenal atresia, multiple jejunal atresias, and apple peel appearance of the remaining ileum in a 3-day-old neonate. Multiple jejunal atresias were resected, and a duodenojejunostomy was performed. Although duodenal atresia is believed to result from failure of vacuolation process, this very rare association of duodenojejunal atresia with apple peel appearance of the ileum suggests that some vascular injury occurring during late gestation might also lead to duodenal atresia

Association of levels of serum inhibin b and follicle-stimulating hormone with testicular vascularity, volume, and echotexture in children with undescended testes

Aims: The aim of our study was to assess the association between reproductive hormones (inhibin B [inh B], follicle-stimulating hormone [FSH]) with testicular volume, echogenicity, and blood flow (resistive index [RI]) in children with undescended testis (UDT). Settings and Design: This was a prospective study of 1-year study duration. Materials and Methods: A total of 33 patients (16 unilateral and 17 bilateral) UDTs aged 5-12 years with palpable UDT were included in the study. Morning fasting blood samples were taken for estimation of serum inh B and FSH as well as inh B/FSH ratio. Testicular ultrasound was done to compute testicular volume, testicular echogenicity, and testicular vascularity in terms of RI. Results: The mean age of patients enrolled in the study was 8.29 years for unilateral UDT and 7.97 years in bilateral UDT and it was comparable. The study groups were further subdivided into two age-wise subgroups school goers (5-8 years) and prepubertal (9-12 years). The values of inh B, FSH, and inh B/FSH ratios as well as mean testicular volume were comparable between both groups and subgroups. Overall mean testicular volume had a positive correlation with FSH, inh B, and inh B/FSH, but statistical significance was reached only for inh B (P 0.6 were separately studied. The incidence of high RI (>0.6) was also comparable in unilateral or bilateral disease. These subjects had unfavorable biochemical parameters in terms of low inh B levels and high FSH levels. Conclusions: Our findings hint to the fact that palpable UDT forms a homogenous group, whether unilateral or bilateral, whereas impalpable testes may form a separate category and need further studies to substantiate this hypothesis