Impact of Thermal Aging on the Microstructure Evolution and Mechanical Properties of Lanthanum-Doped Tin-Silver-Copper Lead-Free Solders

The authors would like to thank Ste´phanie Blanc (Electrical Engineer at Schlumberger) for her useful contribution to the project, Claude Guyomard and Olivier Naegelen (Arts et Me´tiers ParisTech) for the die design and sample casting, respectively, and Jean-Marc Raulot for his enriching discussions.An extensive study is made to analyze the impact of pure lanthanum on the microstructure and mechanical properties of Sn-Ag-Cu (SAC) alloys at high temperatures. Different compositions are tested; the temperature applied for the isothermal aging is 150 C, and aging times of 10 h, 25 h, 50 h, 100 h, and 200 h are studied. Optical microscopy with cross-polarized light is used to follow the grain size, which is refined from 8 mm to 1 mm for as-cast samples and is maintained during thermal aging. Intermetallic compounds (IMCs) present inside the bulk Sn matrix affect the mechanical properties of the SAC alloys. Due to high-temperature exposure, these IMCs grow and hence their impact on mechanical properties becomes more significant. This growth is followed by scanning electron microscopy, and energy-dispersive spectroscopy is used for elemental mapping of each phase. A significant refinement in the average size of IMCs of up to 40% is identified for the as-cast samples, and the coarsening rate of these IMCs is slowed by up to 70% with no change in the interparticle spacing. Yield stress and tensile strength are determined through tensile testing at 20 C for as-cast samples and after thermal aging at 150 C for 100 h and 200h. Both yield stress and tensile strength are increased by up to 20% by minute lanthanum doping

Noise-robust preparation contextuality shared between any number of observers via unsharp measurements

Multiple observers who independently harvest nonclassical correlations from a single physical system share the system's ability to enable quantum correlations. We show that any number of independent observers can share the preparation contextual outcome statistics enabled by state ensembles in quantum theory. Furthermore, we show that even in the presence of any amount of white noise, there exists quantum ensembles that enable such shared preparation contextuality. The findings are experimentally realised by applying sequential unsharp measurements to an optical qubit ensemble which reveals three shared demonstrations of preparation contextuality.Comment: H. A. and N. W. contributed equally to this wor

Impact of Global Economic Meltdown on Property Development in Bauchi, Nigeria

The global economic meltdown is a situation in which the economy of a country experiences a sudden downturn brought on by a financial crisis. This global recession was caused by so many factors, thus, inflation rate, exchange rate, interest rate, unemployment rate, etc. This paper examined the impact of the global economic meltdown on property development in Bauchi, Nigeria. Data for the study are mainly primary in the form of questionnaires administered. The study had property development as an endogenous variable while a high-interest rate and unemployment rate as exogenous variables to measure the constructs. Multiple Regression were used to analyze the data. Among the study, findings are that high relationship exists between the two predictor variables (High-Interest Rate & Unemployment Rate) and dependent variable (property Development) where ‘R’ of 0.724 means the correlation is about 72 %; with R2 of 0.052 indicate that 5.2 % correlation, the analysis also depict in coefficient table that high-interest rate has more influence on dependent variable (PD) than unemployment rate. The analysis signified that the impact of the global economic meltdown has a positive effect on the dependent variable. Based on the findings, the study recommended governments and financial institutions intervention to curb the impediment of property development in Bauchi, Nigeria

Steering is an essential feature of non-locality in quantum theory

A physical theory is called non-local when observers can produce instantaneous effects over distant systems. Non-local theories rely on two fundamental effects: local uncertainty relations and steering of physical states at a distance. In quantum mechanics, the former one dominates the other in a well-known class of non-local games known as XOR games. In particular, optimal quantum strategies for XOR games are completely determined by the uncertainty principle alone. This breakthrough result has yielded the fundamental open question whether optimal quantum strategies are always restricted by local uncertainty principles, with entanglement-based steering playing no role. In this work, we provide a negative answer to the question, showing that both steering and uncertainty relations play a fundamental role in determining optimal quantum strategies for non-local games. Our theoretical findings are supported by an experimental implementation with entangled photons.Comment: 16 pages, 5 figure

Cryptanalysis on prime power RSA modulus of the form N=prq

Let $N = p^r q$ be an RSA prime power modulus for $r \geq 2$ and $q < p < 2 q$. This paper propose three new attacks. In the first attack we consider the class of public exponents satisfying an equation $e X - N Y = u p^r + \frac{q^r}{u} + Z$ for suitably small positive integer $u$. Using continued fraction we show that $\frac{Y}{X}$ can be recovered among the convergents of the continued fraction expansion of $\frac{e}{N}$ and leads to the successful factorization of $N p^r q$. Moreover we show that the number of such exponents is at least $N^{\frac{r+3}{2(r+1)}-\varepsilon}$ where $\varepsilon \geq 0$ is arbitrarily small for large $N$. The second and third attacks works when $k$ RSA public keys $(N_i,e_i)$ are such that there exist $k$ relations of the shape $e_i x - N_i y_i = p_i^r u + \frac{q_i^r}{u} + z_i$ or of the shape $e_i x_i - N_i y = p_i^r u + \frac{q_i^r}{u} + z_i$ where the parameters $x$, $x_i$, $y$, $y_i$, $z_i$ are suitably small in terms of the prime factors of the moduli. We apply the LLL algorithm, and show that our strategy enable us to simultaneously factor the $k$ prime power RSA moduli $N_i$

Anti-oncogenic perspectives of spices/herbs

Contemporary nutrition regime has focused the attention of the researchers on phytochemicals enriched spices to mitigate various oncological threats. Numerous chemopreventive strategies against malignancy have been developed considering the anticancer perspectives of allied nutraceutical constituents. Current evidences have proven an inverse association of spices with that of oncological incidences. The high antioxidant activity of spices derived bioactives triggers the free radicals scavenging ability at cellular level thereby alleviating various metabolic syndromes. Promising compounds including curcumin and curcuminoids (turmeric), limonene (cardamom), allicin, allyl isothiocyanate (garlic), cinnamic aldehyde, 2-hydroxycinnamaldehyde and eugenol (cinnamon), gingerol, zingiberone, zingiberene (ginger), dipropyle disulfides and quercetin (onion), piperidine piperine, limonene, α- and β-pinene (black pepper), crocetin, crocin and safranal (saffron) have been identified as chemopreventing agents against various malignancies. Chemopreventive properties of spices are mediated by functional bioactive ingredients that arrest the activity of cytochrome P450 and isozymes CYP 1A1, cyclooxygenase-2, reducing activator of transcription-3 (STAT-3) and signal transducer. They are closely associated with tumorigenesis activated by interleukin-6 (IL-6) receptors and epidermal growth factor (EGF) relate to an array of tumors. The bioactive constituents altering the expression of protein involved in cell cycle, activating caspases killer and suppressing Kappa-B activation. Alongside, they also restrain causative agents of cell structure damage as in lipid and protein membrane system and DNA that shifting healthy body towards cancerous state. Spices phytochemicals have established as carcinogenesis blockers by modulating cell proliferation pathways transformation, inflammation, metastasis etc. Furthermore, spices as functional ingredients may act as immune boosters and diminish inflammatory disorders. The current review is inevitably an affirmative approach in the development of novel guidelines against cancer by using dietary species to maintain good health