Two-dimensional (2D) materials are a new type of materials under intense study because of their interesting physical properties and wide range of potential applications from nanoelectronics to sensing and photonics. Monolayers of semiconducting transition metal dichalcogenides MoS2 or WSe2 have been proposed as promising channel materials for field-effect transistors. Their high mechanical flexibility, stability, and quality coupled with potentially inexpensive production methods offer potential advantages compared to organic and crystalline bulk semiconductors. Due to quantum mechanical confinement, the band gap in monolayer MoS2 is direct in nature, leading to a strong interaction with light that can be exploited for building phototransistors and ultrasensitive photodetectors. Here, we report on the realization of light-emitting diodes based on vertical heterojunctions composed of n-type monolayer MoS2 and p-type silicon. Careful interface engineering allows us to realize diodes showing rectification and light emission from the entire surface of the heterojunction. Electroluminescence spectra show clear signs of direct excitons related to the optical transitions between the conduction and valence bands. Our p–n diodes can also operate as solar cells, with typical external quantum efficiency exceeding 4%. Our work opens up the way to more sophisticated optoelectronic devices such as lasers and heterostructure solar cells based on hybrids of 2D semiconductors and silicon.

http://absimage.aps.org/image/MAR14/MWS_MAR14-2013-004565.pdf

Light Generation and Harvesting in a Van der Waals Heterostructure

Recent advances in eco-friendly and cost-effective materials towards sustainable dye-sensitized solar cells

The dissipated power and the directivity of antennas in a homogeneous, lossy
medium are systematically analyzed in this paper. The antennas are ideal
and located inside a lossless sphere. In the lossy space outside the sphere, the
electromagnetic ﬁelds are expanded in a complete set of vector wave functions.
The optimal values of the radiation eﬃciency, the directivity, as well as the
power gain are derived.

Physical limitations of antennas in a lossy medium

We investigate Atomic Layer Deposition (ALD) of metal oxide on pristine and functionalized graphene. On pristine graphene, ALD coating can only actively grow on edges and defect sites, where dangling bonds or surface groups react with ALD precursors. This affords a simple method to decorate and probe single defect sites in graphene planes. We used perylene tetracarboxylic acid (PTCA) to functionalize graphene surface and selectively introduced densely packed surface groups on graphene. Uniform ultrathin ALD coating on PTCA graphene was achieved over large area. The functionalization method could be used to integrate ultrathin high-k dielectrics in future graphene electronics.

Atomic Layer Deposition of Metal Oxides on Pristine and Functionalized Graphene

Nickel-manganese phosphate: An efficient battery-grade electrode for supercapattery devices

A compact hairpin line bandpass filter is presented with two different defected ground structures (DGS). The DGS are used to reduce the distributive response of the microstrip filter. The harmonic at 2 fo is suppressed to below −20 dB. The filter has an insertion loss (IL) greater than −3 dB and return loss (RL) of 26 dB at the center frequency, 2.4 GHz. The designed filter has a sharp roll-off and a wide band of operation. The filter is fabricated using RO4350 substrate and measured results are compared with the simulations.

A Compact Hairpin Filter with Stepped Hairpin Defected Ground Structure

A 1:16 Wilkinson power divider (WPD) working from 1.3 GHz to 3 GHz is presented in this paper. Equal power division, phase and amplitude consistency is achieved among the output ports. The proposed design has a wideband with a 10 dB fractional bandwidth of 76%. The isolation loss within the bandwidth is better than 15 dB and the insertion loss is less than 2 dB. The size of the WPD has been minimized to 16×10.7 cm2, which was the main objective of this work. The compact size of the proposed design makes it a suitable candidate for feeding phased antenna arrays for wideband operations.

ISM Band 1:16 Wilkinson Power Divider

Thermistors exhibit a nonlinear temperature-resistance response, due to which corrections have to be made when making temperature measurements. In this paper a bio - sensor system is proposed that provides a convenient and non-bulky means of using thermistors in temperature measurements. The system works by maintaining a set point using negative feedback. Compared to traditional thermistor systems, that use linearization technique to improve the linearity of the non-linear response of thermistor, the proposed system uses the graphical approach, hence reducing hardware and eliminating bulky calculations. PIC16F877A micro controller is used for the analysis of data from the patients’ end that is then interfaced through USB (Universal Serial Bus) to the software programmed using LAB WINDOWS/CVI 8.0. Biosensor used to test the response of this system is 400 series thermistor as it is sufficiently stable, low cost and has simple interfacing requirements. Also, a communication network based on Star Topology is designed for transferring temperature data from the subject’s site to the physician’s panel and in turn transferring instructions from main server to the client.

A Novel Body Temperature Measuring and Data Transmitting System Using Bio - Sensors and Real-Time Transmission Technique

Mind Synchronization is an attempt to make a voiceless communication, without using tongue, indications, or gestures. It is to entertain the medical field in making devices which can help deaf and dumb people to express and deliver their thoughts with their counterparts and an attempt to make a system in which a subject just has to think of a word in his conscious mind and it can be conveyed to the desired destination securely, silently and accurately. When a person initializes his brain to say something, an image of the word or alphabets are portrayed at the back of his mind. This process has been done less than a second that’s why no one can notice this through a naked eye, scientifically, it is proved that anything a man thinks or tries to convey is stored in subconscious mind in the form of an image. Every alphabet thought in mind results with the slight change in the Electroencephalogram of the person. This slight change distinguished and used to make this project working. The suggested method investigates the usefulness of Time – Frequency Analysis as a methodology for classifying various alphabets using electroencephalogram (EEG). For signal acquisition the Electrodes are placed on a subject scalp followed by Instrumentation amplifier which consisting of two stage amplifier i.e., (OPAMP INA118 and TL082), optocoupler subject projection circuit has also been designed for the safety of circuit and the subject too, along with these circuitry Right Driven Leg circuit has also designed to reduce Common-mode interference during acquiring the brain EEG signal from a subject. Narrow band multi feedback filter were also designed to just detect the Alpha wave activity of the subject brain because of aim of this project just to detect these waves for this purpose (8 to 13 HZ) narrow band filleter designed at these ranges. TMS320C6713 digital signal processing kit was also used to perform periodogram on the acquired EEG and extracting the local maxima of the input acquired for the further analysis. The results suggest this approach can retrieve alphabets in half a second. Up to the full number of methods can be used for EEG signal detection to differentiate alphabets. Ranges of data for some alphabets are also collected.

An EEG analysis approach towards brain-to-brain synchronization

Objective: To compare the metabolic outcomes in psychiatric patients treated with Olanzapine and Risperidone
Study Design: Quasi experimental study
Place and Duration of Study: The study was conducted at Armed Forces Institute of Mental Health, Rawalpindi,from Aug 2016 to Jan 2017
Methodology: In this study 114 newly diagnosed psychiatric patients taking atypical anti-psychotics were selected and placed randomly into two groups ie group A (Olanzapine) andgroup B (Risperidone), 57 patients each Patients of either gender, 20 to 60 years’ age, clinically diagnosed new cases having psychiatric illness using DSMV were selected consecutively Baseline and six months’ end study data were collected and compared
Results: Total 14 out of 109 (5 patients lost follow up) patients developed metabolic syndrome Among these 10(1818%) were in group A while 4 (741%) were in group B Patients receiving Olanzapine were 258 times moreprone to develop metabolic syndrome compared to the Risperidone receiving [RR= 258 {CI 085009, 762703}]Weight gain (p-value = 00048), increased Waist circumference (p-value = 000867) and elevated Blood Pressure (pvalue = 00563) were seen more significantly with use of Olanzapine
Conclusion: Olanzapine although associated with good efficacy but indeed with more serious and long-term side effects like impaired blood glucose tolerance, dyslipidemia and increase weight Psychiatrist must screen and continuously monitor such patients

/pdf/comparison-of-two-widely-used-atypical-antipsychotics-2jp5ngynt8.pdf

Sana Khan

Papers

A Compact Hairpin Filter with Stepped Hairpin Defected Ground Structure

ISM Band 1:16 Wilkinson Power Divider

A Novel Body Temperature Measuring and Data Transmitting System Using Bio - Sensors and Real-Time Transmission Technique

An EEG analysis approach towards brain-to-brain synchronization

Comparison of two widely used atypical antipsychotics olanzapine versus risperidone in terms of metabolic outcomes