Effect of Co-60 gamma-ray irradiation on electrical properties of Ti/Au/GaAs1-xNx Schottky diodes

Current-voltage (I-V), capacitance-voltage-frequency (C-V-f) and conductance-voltage-frequency (G/ω-V-f) measurements at room temperature are used to study 50 kGy 60Co γ-ray electrical properties irradiation dependence of Ti/Au/GaAs1−xNx Schottky diodes with 0.2%; 0.4%; 0.8% and 1.2% nitrogen dilution. This γ-ray irradiation induces a permanent damage that has increased ideality factor and series resistance for all samples. It was accompanied by a decrease in Schottky barrier height with nitrogen content up to 0.4%N and remained constant thereafter. Radiation was also found to degrade the reverse leakage current. At high frequency (1 MHz), capacitance and conductance decreased after radiation due to a decrease in net doping concentration. Interface state density and series resistance were determined from C-V-f and G/ω-V-f characteristics using Hill-Coleman methods. Interface states density exponentially decreased with increasing frequency confirming the behavior of interface traps response to ac signal. Series resistance increases after irradiation is attributed to carrier's removal effect and mobility degradation. It has two peaks in the accumulation and inversion region for some diodes (0.4%N, 0.8%N). γ-ray irradiation produced traps levels and recombination centers that reduce relaxation time. An increase in %N content can impede irradiation damage with even some compensation when the percent of diluted nitrogen is high (1.2%N)

Pathways to a more peaceful and sustainable world:The transformative power of children in families

This article provides an overview of selected ongoing international efforts that have been inspired by Edward Zigler’s vision to improve programs and policies for young children and families in the United States. The efforts presented are in close alignment with three strategies articulated by Edward Zigler: (a) conduct research that will inform policy advocacy; (b) design, implement, and revise quality early child- hood development (ECD) programs; and (c) invest in building the next generation of scholars and advocates in child development. The intergenerational legacy left by Edward Zigler has had an impact on young children not only in the United States, but also across the globe. More needs to be done. We need to work together with a full commitment to ensure the optimal development of each child

On the profile of frequency dependent interface states and series resistance in Au/p-InP SBDs prepared with photolithography technique

The frequency dependent of the forward and reverse bias capacitance-voltage (C-V) and conductance-voltage (G/w-V) characteristics of Au/p-InP SBDs have been investigated in the frequency range of 20 kHz-10 MHz and voltage range of -5 - 5 V at room temperature. The effects of surface states (N (ss)) and series resistance (R (s)) on C-V and G/w-V characteristics have been investigated in detail. The frequency dependent N (ss) and R (s) profiles were obtained for various applied bias voltages. The experimental results show that the main electrical parameters of Au/p-InP SBD such as barrier height (I broken vertical bar(B)), the density of acceptor concentration (N (A)), N (ss) and R (s) were found strongly frequency and voltage dependent. The values of C and G/w decrease with increasing frequency due to a continuous distribution of N (ss) localized at the metal/semiconductor (M/S) interface. The effect of R (s) on C and G is found considerably high especially at high frequencies. Therefore, the high frequencies of the values of C and G were corrected for the effect of R (s) in the whole measured bias range to obtain the real diode capacitance C (c) and conductance G (c) using the Nicollian and Goetzberger technique. The distribution profile of R (s)-V gives a peak depending on the frequency especially at low frequencies and disappears with increasing frequencies due to the existence of N (ss) at the M/S interface

The relationship between serum estrogen concentration and post-dural puncture headache: a retrospective study

OBJECTIVE: Post-Dural puncture headache (PDPH) is a severe and undesirable complication for the patient and anesthesiologist. PDPH is more common in female patients. However, its relationship with plasma estrogen levels has not been demonstrated. This study aimed to investigate the relationship between estrogen levels and PDPH in patients who underwent spinal anesthesia for in vitro fertilization (IVF) with supraphysiological estrogen levels. PATIENTS AND METHODS: In this retrospective study, the data of patients between the ages of 18-45 with the following characteristics were included in the study: those who underwent IVF procedure between January 2021 and August 2022, in the ASA I-II risk group, and who underwent spinal anesthesia using a 25 G Quinke-tipped spinal needle at the L3-L4 or L4-L5 vertebra levels. The 48 patients in the study were in two groups according to their estradiol values: ‘Supra physiological estradiol levels’ (Group I=24 patients) and ‘Normal estradiol levels’ (Group C=24 patients). The relationship between PDPH and estrogen, progesterone, spinal needle diameter, and patient demographic characteristics were evaluated. RESULTS: The estrogen and progesterone levels of patients in Group I were higher than in Group C (p0.05). CONCLUSIONS: Since there is no relationship between the supraphysiological estrogen level and PDPH, high serum estrogen level should not be considered as an additional risk factor for PDPH in the decision of anesthesia type for IVF procedure

Origin of forward bias capacitance peak and intersection behavior of C and G/w of Ag/p-InP Schottky barrier diodes

Frequency-dependent electrical characteristics of Ag/p-InP diodes have been determined using impedance spectroscopy at room temperature. Series resistance (R,) and interface state(s) (N-ss) values were extracted from capacitance (C) and conductance (G/w) data using the Nicollian and Goetzberger and Hill-Coleman methods, respectively. C and G/w data were also corrected in the whole measured bias voltage range to obtain real diode capacitance C-c and conductance G(c) values in order to see the effects of R-s. Both the C-V and R-s-V plots showed anomalous peak in depletion region especially at low frequencies due to the existence of N-ss. C-V and G/w-V plots crossed at a certain bias voltage and this point shifted toward negative bias voltages with increasing frequency and then disappeared at 3 MHz. Also, decrease in C values corresponds to an increase in G/w values in the same bias voltages

Effect of pre-fermented juice, Lactobacillus plantarum and lactobacillus buchneri on the fermentation characteristics and aerobic stability of high dry matter alfalfa bale silage

The experiment was conducted to investigate the effects of pre-fermented juice (PFJ), Lactobacillus plantarum and Enterococcus faecium (LP), and Lactobacillus buchneri (LB) on the fermentation characteristics and aerobic stability of alfalfa bale silage. The herbage was wilted to 602.3 g/kg dry matter (DM). Treatments of alfalfa silage included (1) control; (2) PFJ: 2.6×105 colony-forming units (cfu/g); (3) LP: 1.0×106 cfu/g Lactobacillus plantarum and Enterococcus faecium (Pioneer 1188, USA) and (4) LB: 1.0×106 cfu/g Lactobacillus buchneri (Pioneer 11A44) and baled, 150 days. At the end of the ensiling period, three bales of each treatment group were opened, chemical and microbiological analyses were made. Consequently, lactic acid bacteria inoculants and PFJ increased the quality of alfalfa silages. In terms of aerobic stability, PFJ and LP used had a positive effect on CO2 concentrations coliform bacteria and yeast. Also, LB inoculant decreased NDF content and increased in vitro organic matter digestibility of silages. A total number of 15 representatives of lactic acid bacterial strains were retained and among them 3 dominant genus were identified as Lactobacillus plantarum (46.66%), Lactobacillus pentosaceus (33.33%) and Lactobacillus collinoides (20%). It can be concluded that PFJ can be used as silage additive alfalfa bale silage in farm condition. © 2017, Pakistan Agricultural Scientists Forum. All rights reserved

Parallel-leaky capacitance equivalent circuit model for MgO magnetic tunnel junctions

10.1063/1.4760279Applied Physics Letters10116-APPL