Structural, FTIR, Optical and Dielectric Properties of Zn1-xAlxO Ceramics For Advanced Applications

We report here the structural, FTIR, optical and dielectric properties of Zn1−xAlxO with x = 00.00 < x ≤ 0.20)). The wurtzite structure is conformed to all samples and the lattice constants, crystallite diameter, porosity and average crystalline size are generally decreased. The residual stress is compressive for pure samples, but it is changed to tensile for the doped samples. Interestingly, Debye temperature and elastic modulus are increased as x increases to 0.10, followed by a decrease at x = 0.20. Two different energy gaps Egh and Egl are apparent for each sample, corresponding of two transition absorption peaks. Interestingly, the ΔE = (Egh – Egl) ~ 0.60 for all samples. Further, the residual dielectric constant is decreased by increasing x to 0.10, followed by a sharp increase at x = 0.20 while the opposite behavior for (N/m*). The dielectric constant ε′ is slightly increased as x increases to 0.025, followed by a sharp increase as x increases to 0.20, as well as the ac conductivity σ/. The conduction is electronic for x ≤ 0.025 samples, but it is changed to hole with an increase of x to 0.20. The binding energy Wm was decreased as x increases to 0.20, but there is no exact trend against x for the behaviors of minimum hopping distance Rmin and density of localized states N. In addition, the density of states at Fermi level N (EF) has an optimum value at 195 KHz for all samples. The F-factor for solar cell design is increased as x increases to 0.10, but it is almost constant at x = 0.20. The Cole-Cole plot is a straight line for x = 0.00, a semicircle arc for x = 0.025 and a complete semicircle for x ≥ 0.05. The impedance resistance of grain Z\(g) and grain boundaries Z\(gb) are gradually decreased by increasing x to 0.20. These outcomes indicate that the addition of Al to ZnO shifts the mechanical, optical, and dielectric medium to higher values, which is strongly recommended for the design of optoelectronic and solar cell instruments.

A Hidden Legacy

This biography of Esther Zimmer Lederberg highlights the importance of her research work, which revealed the unique features of bacterial sex, essential for our understanding of molecular biology and evolution. A Hidden Legacy relates how, she and her husband Joshua Lederberg established the new field of bacterial genetics together, in the decade leading up to the discovery of the DNA double helix. Their impressive series of achievements include: the discovery of λ‎ bacteriophage and of the first plasmid, known as the F-factor; the demonstration that viruses carry bacterial genes between bacteria; and the elucidation of fundamental properties of bacterial sex. This successful collaboration earned Joshua the 1958 Nobel Prize, which he shared with two of Esther’s mentors, George Beadle and Edward Tatum. Esther Lederberg’s contributions, however, were overlooked by the Nobel committee, an example of institutional discrimination known as the Matilda Effect. Esther Lederberg should also have been recognized for inventing replica plating, an elegant technique that she originated by re-purposing her compact makeup pad as a kind of ink stamp for conveniently transferring bacterial colonies from one petri dish to another. Instead, the credit for the invention is given to her famous husband, or, at best, to Dr. and Mrs. Lederberg. Within a few years of winning the Nobel Prize, Joshua Lederberg divorced his wife, leaving Esther without a laboratory, cut off from research funding, and facing uncertain employment. In response, she created a new social circle made up of artists and musicians, including a new soulmate. She devoted herself to a close-knit musical ensemble, the Mid-Peninsula Recorder Orchestra, an avocation that flourished for over forty years, until the final days of her life.

Strange Genetics

This chapter relates how, in the 1950s, Esther and Joshua Lederberg and their colleagues uncovered a whole new kind of genetic transfer involving plasmids and viruses. In plants and animals, genetic recombination is integrated within the processes of sexual reproduction. Imagine if you could trade genes with strangers at will! That’s what bacteria can do. Esther Lederberg’s discoveries of the F-plasmid and the λ‎ bacteriophage were happy accidents that occurred while she working to complete her dissertation research. Serendipity happens to those who are very attentive, broadly experienced, and open to surprises. Esther Lederberg discovered a transferable factor, the F-factor, that could transform recipients into donors. Then she discovered a lysogenic virus, hiding harmlessly inside the chromosome of its bacterial host. These two surprising discoveries showed that bacteria could transfer genes and pieces of chromosomes horizontally, as opposed to the classical inheritance of plants and animals which pass on genetic traits vertically, down through generations.

Analisis Faktor-Faktor yang Mempengaruhi Keputusan Mahasiswa dalam Memilih Studi Online Program Sarjana dan Diploma di UPBJJ Ut Jambi

The purpose of this study was to determine (1) the description of student decisions in choosing online studies at UPBJJ UT Jambi, and (2) the factors that influence student decisions in choosing online studies at UPBJJ UT Jambi. The results showed that (1) the student's decision variable in choosing online studies was in the high category with an average of 4.29 and the Respondent Achievement Level (TCR) of 85.81, (2) There were 6 (six) dominant factors that influenced the decision. students in choosing online studies, namely (a) Factor 1 which is given the identity of the Motivation, which consists of statement items F8, F9, F10, F11, and F12, (b) Factor 2 which is given the identity of the Reference Group, which consists of statement items F19 , F20, and F21, (c) Factor 3 which is given the identity of Belief and Attitude, which consists of statement items F4, F16, F17, and F18, (d) Factor 4 which is given the identity of Economic State, which consists of statement items F3, F5, and F6, (e) Factor 5 which is given the identity of Perception, which consists of statement items F14, F15, and F26, and (f) Factor 6 which is assigned the identity of Role and Status, which consists of statement items F23, F24, and F25.

Codegree Threshold for Tiling Balanced Complete $3$-Partite $3$-Graphs and Generalized $4$-Cycles

Given two $k$-graphs $F$ and $H$, a perfect $F$-tiling (also called an $F$-factor) in $H$ is a set of vertex-disjoint copies of $F$ that together cover the vertex set of $H$. Let $t_{k-1}(n, F)$ be the smallest integer $t$ such that every $k$-graph $H$ on $n$ vertices with minimum codegree at least $t$ contains a perfect $F$-tiling. Mycroft (JCTA, 2016) determined the asymptotic values of $t_{k-1}(n, F)$ for $k$-partite $k$-graphs $F$ and conjectured that the error terms $o(n)$ in $t_{k-1}(n, F)$ can be replaced by a constant that depends only on $F$. In this paper, we determine the exact value of $t_2(n, K_{m,m}^{3})$, where $K_{m,m}^{3}$ (defined by Mubayi and Verstraëte, JCTA, 2004) is the 3-graph obtained from the complete bipartite graph $K_{m,m}$ by replacing each vertex in one part by a 2-elements set. Note that $K_{2,2}^{3}$ is the well known generalized 4-cycle $C_4^3$ (the 3-graph on six vertices and four distinct edges $A, B, C, D$ with $A\cup B= C\cup D$ and $A\cap B=C\cap D=\emptyset$). The result confirms Mycroft's conjecture for $K_{m,m}^{3}$. Moreover, we improve the error term $o(n)$ to a sub-linear term when $F=K^3(m)$ and show that the sub-linear term is tight for $K^3(2)$, where $K^3(m)$ is the complete $3$-partite $3$-graph with each part of size $m$.