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Influence of Au on Ge Crystallization and Its Thermoelectric Properties in a Au-induced Ge Crystallization Technique
Get PDFPoly-crystalline Ge (pc-Ge) thin films were prepared on a SiO2/Si substrate using Au-induced crystallization (GIC) of amorphous Ge (a-Ge) with an annealing temperature around the eutectic point of Au-Ge alloy system (361ºC) in order to shorten the annealing time. Bilayer thin films of Au (20 nm)/a-Ge (100 nm) were used as a precursor material and annealed at 300, 400, and 500 ºC for 60 min, which successfully leads to the formation of pc-Ge layers. Characterizing the prepared Ge layers, the crystallographic properties indicated that the metal catalyst Au plays a notable role of enhancing both the crystallization and the island formation of Ge layers. It was also shown that the pc-Ge hardly contains Au atoms. Therefore, the Seebeck coefficient was hardly influenced by Au atoms since they do not act as a carrier source. In addition, the thermal conductivity of the pc-Ge film prepared by the GIC method was higher than that formed without Au, which is not due to the Au catalyst itself but due to the crystallinity of Ge film enhanced by the Au atoms
Modification in Bi-Ag Lead-Free Solder-Bearing Alloying Elements
Get PDFThe development of lead-free solder has an urgent task for material scientist due to health and environmental concerns over the lead content of traditional solders. The objective of this study is to examine Bi-Ag-rare earth (RE) element considered as one of the more attractive lead-free solders since it can easily replace Sn-Pb eutectic alloy with increasing soldering temperature while causes for high-temperature applications. In order to enhance the soldering properties of Bi-Ag alloys, a trace eare earth (RE) element of Ho added into Bi-Ag alloys. The results indicated that the addition of RE led to the refining of coarse Bi-Ag grains, in the microstructure. The tensile strength, Hv and creep resistance increased with a decrease in melting point and electrical resistance. This paper brief the influences of rare earth alloying element and rapid solidification on both of the microstructure, intermetallic compounds, creep resistance, melting behavior, electrical resistance and mechanical behavior
Preparation and Characterization of Polyacrylamide – Silver Nanocomposite
Get PDFThe preparation of polyacrylamide (PAAM)/silver (Ag) nanocomposites, transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and vibrational structure were studied in this work. TEM results showed that the Ag particles were in sphere shape with 12 nm and 13 nm diameter. The X-ray diffraction results showed that, silver nanoparticles are present in the prepared nanocomposites 10 nm and 11 nm. The vibrational modes were analyzed by FTIR spectroscopy
On The Bosons’ Range of the Weak Interaction
Get PDFAs known the Weak Nuclear Force or Weak Interaction(WI) acts between quarks (Qs) and leptons. The action of the WI is mediated by highly massive gauge bosons. How does a nuclear Q emit such a massive particle, approximately 16000 or 40000 times its mass? Who provides so much energy to a up Q or a down Q? However, it must be considered that according to Quantum Mechanics it is possible to loan temporarily some energy, but to a precise and binding condition, established by the Uncertainty Principle: the higher the energy borrowed, the shorter the duration of the loan. Our calculations show that the maximum distance these bosons can travel, i.e. the upper limit of their range, corresponds to 1.543×10-15 [cm] for particles W+ and W- and 1.36×10-15[cm] for Z° particles
Sorption of Ni(II) and Cr(III) ions by the Chironomus yoshimatsui larvae from wastewater
Get PDFIn this study, Chironomus yoshimatsui larvae were applied to remove Ni(II) and Cr(III) ions from wastewater. The sorption studies were carried out using laboratory-reared C. y. larvae. It was found that C. y. larvae are very susceptible to Cr(III) as compared to Ni(II). The survival capacity of C. y. larvae was sharply reduced when exposed to even low Cr(III) concentration. Sorption isotherm and kinetics of C. y. larvae for Ni(II) were determined by means of controlled experiments in a batch system. It was observed that sorpyion efficiency of Ni(II) was largely concentration dependent and more effective at lower concentration. At each equilibrium, Ni(II) was removed up to roughly 44∼80 %. Sorption data were better fitted to the Langmuir isotherm model because of its correlation coefficient R2 value greater than that of the Freundlich isotherm model. The sorption kinetics by C. y. larvae for Ni(II) was well described a pseudo-first-order rate expression. C. y. larvae have enormous potential for application in wastewater treatment technologies because they are widespread and abundant all around the world and can be easily kept in culture
Argument estimates of certain classes of P-Valent meromorphic functions involving certain operator
Get PDFIn this paper, by making use of subordination , we investigate some inclusion relations and argument properties of certain classes of p-valent meromorphic functions involving certain operator
Multi-Source Backlogged Probabilistic Inventory Model for Crisp and Fuzzy Environment
Get PDFThis paper proposed a multi-item multi-source probabilistic periodic review inventory model under a varying holding cost constraint with zero lead time when: (1) the stock level decreases at a uniform rate over the cycle. (2) some costs are varying. (3) the demand is a random variable that follows some continuous distributions as (two-parameter exponential, Kumerswamy, Gamma, Beta, Rayleigh, Erlang distributions).The objective function under a constraint is imposed here in crisp and fuzzy environment. The objective is to find the optimal maximum inventory level for a given review time that minimize the expected annual total cost. Furthermore, a comparison between given distributions is made to find the optimal distribution that achieves the model under considerations. Finally, a numerical example is applied
Another Proof of Beal's Conjecture
Get PDFBeal's Conjecture : The equation za = xb+yc has no solution in relatively prime positive integers x; y; z with a, b and c odd primes at least 3. A proof of this longstanding conjecture is given
The Classification of Permutation Groups with Maximum Orbits
Get PDFLet G be a permutation group on a set with no fixed points in and let m be a positive integer. If no element of G moves any subset of by more than m points (that is, if for every and g 2 G), and the lengths two of orbits is p, and the restof orbits have lengths equal to 3. Then the number t of G-orbits in is at most Moreover, we classifiy all groups for is hold.(For denotes the greatest integer less than or equal to x.
Evaluation of Using Radiographic Films in Measurements of Penumbra Width for Radiotherapy Applications and Stereotactic Radiosurgery: medical physics
No full textThe accuracy of treatment field size in is a success key in cancer radiotherapy. As Increase in dose may lead to overdose side effects, and decrease in dose lead to subtherapeutic effect which increased incidence of tumor recurrence or incomplete recovery of patient. Many physical parameters should be measured very accurately in order to predict the dose distribution as physical penumbra of radiation fields. Ionization chamber is considered as slandered tools for measuring penumbra. Mega voltage x-ray energy penumbra is measured using ionization chamber due to its high accuracy in measuring absolute dose. This technique can produce the gold standard for penumbra measurements; however, it is a very time consuming and demanding process. Aim of this work is to evaluate the using radiographic films in penumbra width measurements for radiotherapy applications and stereotactic radiosurgery by comparing results obtained by standard ionization chambers to radiographic films as new tool for penumbral width measurements. Comparison between penumbra region measured by ionization chamber and o-xmat v Kodak radiographic films were carried out under the same physical and dosimeteric conditions. Penumbra width differences were found to be less than 1 mm for 6 mev, 15 mev photon beam and 6 mv, 15 mv electron beam used in radiotherapy. Measured differences were considered very small and has no effect on penumbra width measurements however o-xmat v Kodak films provide fast .easy and economic method for penumbra measurement used in radiotherapy dosimetery.