Thermoelectric properties of hot-pressed Ruddlesden-Popper phases CaO(CaMnO3)m

We investigated the Ruddlesden-Popper series CaO(CaMnO₃)_m with m = 1, 2, 3, ∞, to study the impact of the varying amounts of CaO layers on their thermoelectric properties. Previous studies showed that highly dense samples are difficult to obtain due to the refractory nature of these materials. In this study, we managed to obtain dense pellets during a classical hot-pressing step, if and only if the samples were subjected to extended ball-milling prior to pressing, resulting in crystallite sizes of 30–35 nm after hot-pressing. The sample with the largest amount of CaO layers (m = 1) had the lowest electrical and thermal conductivity, and the highest Seebeck coefficient, as predicted. Ultimately the perovskite CaMnO₃ (m = ∞, no CaO layers) exhibited the best thermoelectric properties.     

Free surface planar liquid jet impingement on a moving surface: interfacial flow and heat transfer characteristics

Journal of Mechanical Science and Technology - Understanding heat transfer characteristics of sheet metal is of practical importance in sheet metal rolling operation to ensure strength and quality...     

Feasibility Study of Tuning the Threshold Voltage of Nanoscale Fin-shaped Field Effect Transistor (FinFET) via Metal Gate Workfunction Engineering

Silicon - In this paper, we comprehensively assess the unique features, feasibility and limitations of dual material gate fin field effect transistor for tuning the threshold voltage in nanoscale...     

Hill Matrix and Radix-64 Bit Algorithm to Preserve Data Confidentiality

There are many cloud data security techniques and algorithms available that can be used to detect attacks on cloud data, but these techniques and algorithms cannot be used to protect data from an attacker. Cloud cryptography is the best way to transmit data in a secure and reliable format. Various researchers have developed various mechanisms to transfer data securely, which can convert data from readable to unreadable, but these algorithms are not sufficient to provide complete data security. Each algorithm has some data security issues. If some effective data protection techniques are used, the attacker will not be able to decipher the encrypted data, and even if the attacker tries to tamper with the data, the attacker will not have access to the original data. In this paper, various data security techniques are developed, which can be used to protect the data from attackers completely. First, a customized American Standard Code for Information Interchange (ASCII) table is developed. The value of each Index is defined in a customized ASCII table. When an attacker tries to decrypt the data, the attacker always tries to apply the predefined ASCII table on the Ciphertext, which in a way, can be helpful for the attacker to decrypt the data. After that, a radix 64-bit encryption mechanism is used, with the help of which the number of cipher data is doubled from the original data. When the number of cipher values is double the original data, the attacker tries to decrypt each value. Instead of getting the original data, the attacker gets such data that has no relation to the original data. After that, a Hill Matrix algorithm is created, with the help of which a key is generated that is used in the exact plain text for which it is created, and this Key cannot be used in any other plain text. The boundaries of each Hill text work up to that text. The techniques used in this paper are compared with those used in various papers and discussed that how far the current algorithm is better than all other algorithms. Then, the Kasiski test is used to verify the validity of the proposed algorithm and found that, if the proposed algorithm is used for data encryption, so an attacker cannot break the proposed algorithm security using any technique or algorithm.     

Zinc-based metal-organic frameworks: synthesis and recent progress in biomedical application

Journal of Inorganic and Organometallic Polymers and Materials - This review based on Zn-based MOF is summarized on new insights for targeted drug delivery of medicinal compounds and developed for...     

Synthesis and utilization of mesoporous alumina as a supporting material of Ce-promoted Ni-based catalysts in the methane reforming process

Due to the large applications of hydrogen as a feedstock of chemical industries and as an energy carrier, its production on large scales with low costs has attracted researchers. Steam reforming of methane (SRM) is the most common process for producing H₂-rich syngas over Ni/Al₂O₃ catalysts, which suffer from coke deposition and Ni particles agglomeration. For overcoming these issues, we have synthesized mesoporous alumina (MA) as a supporting material of Ni particles, structure, and activity, which were compared with the bulk alumina (BA) supported catalysts in the SRM process for the first time. Besides, cerium as an appropriate promoter for lowering deposited coke was added to all prepared catalysts. The reaction temperature (600–700°C), Ni loading (10–25 wt.%), and Ce loading (1–5 wt.%) were the parameters that were optimized for maximizing H₂ yield and CH₄ conversion. Prepared samples were characterized by various techniques before and/or after reaction. The results of TEM and XRD depicted the formation of nanocrystalline and mesoporous structure for Ni-MA catalysts compare to Ni-BA samples. The observations indicated that 20Ni-3Ce/MA had the highest catalytic performance, achieving a CH₄ conversion of 91.0% and H₂ yield of 92.8% at 700°C.