Measurement of Excess Molar Enthalpies of Binary and Ternary Systems Involving Hydrocarbons and Ethers

The study of excess thermodynamic properties of liquid mixtures is very important for designing the thermal separation processes, developing solution theory models and to have a better understanding of molecular structure and interactions involved in the fluid mixtures. In particular, heat of mixing or excess molar enthalpy data of binary and ternary fluid mixtures have great industrial and theoretical significance. In this connection, the experimental excess molar enthalpies for seventeen binary and nine ternary systems involving hydrocarbons, ethers and alcohol have been measured at 298.15K and atmospheric conditions for a wide range of composition by means of a flow microcalorimeter (LKB 10700-1). The binary experimental excess molar enthalpy values are correlated by means of the Redlich-Kister polynomial equations and the Liebermann - Fried solution theory model. The ternary excess molar enthalpy values are represented by means of the Tsao-Smith equation with an added ternary term and the Liebermann-Fried model was used to predict ternary excess molar enthalpy values. The Liebermann-Fried solution theory model was able to closely represent the experimental excess enthalpy data for most of the binary and ternary systems with reasonable accuracy. The correlated and predicted excess molar enthalpy data for the ternary systems are plotted in Roozeboom diagram

Stability study: Transparent conducting oxides in chemically reactive plasmas

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Effect of plasma treatment on transparent conductive oxides (TCOs) including indium-doped tin oxide (ITO), fluorine-doped tin oxide (FTO) and aluminium-doped zinc oxide (AZO) are discussed. Stability of electrical and optical properties of TCOs, when exposed to plasma species generated from gases such as hydrogen and silane, are studied extensively. ITO and FTO thin films are unstable and reduce to their counterparts such as Indium and Tin when subjected to plasma. On the other hand, AZO is not only stable but also shows superior electrical and optical properties. The stability of AZO makes it suitable for electronic applications, such as solar cells and transistors that are fabricated under plasma environment. TCOs exposed to plasma with different fabrication parameters are used in the fabrication of silicon nanowire solar cells. The performance of solar cells, which is mired by the plasma, fabricated on ITO and FTO is discussed with respect to plasma exposure parameters while showing the advantages of using chemically stable AZO as an ideal TCO for solar cells. Additionally, in-situ diagnostic tool (optical emission spectroscopy) is used to monitor the deposition process and damage caused to TCOs

Copper complex of isatin Schiff base encapsulated in zeolite as active heterogeneous catalyst: an efficient protocol for the acetylation reaction

Copper (II) complex of 3-phenylimino-1,3-dihydro-indol-2-one encapsulated in the super cages of zeolite-Y has been synthesized by flexible ligand method and characterized by various physicochemical measurements. The catalytic activity of cationic exchanged zeolite, copper complex of ligand and complex encapsulated inside the zeolite was investigated for the decomposition of H2O2 and for the acetylation of p-cresol. All catalysts show good to excellent yield. The results showed that conversion of p-cresol varies in the order homogeneous complex \NaY-Zeolite\Cu-Y-Zeolite\heterogeneous comple

Comparative Study of Silicon Nanowires Grown From Ga, In, Sn, and Bi for Energy Harvesting

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.A high density of silicon nanowires for solar cell applications was fabricated on a single crystalline silicon wafer, using low eutectic temperature metal catalysts, namely, gallium, indium, tin, and bismuth. The use of silicon nanowires is exploited for light trapping with an aim to enhance the efficiency of solar cells. Additionally, we have optimized the deposition parameters so that there is merely deposition of amorphous silicon along with the growth of silicon nanowires. Thus, it may improve the stability of silicon-based solar cells. The different catalysts used are extensively discussed with experimental results indicating stable growth and highly efficient silicon nanowires for photovoltaic applications. To test the stability, we measured the open-circuit voltage for four hours and the change in voltage was ±0.05 V. The fabrication of all-crystalline silicon solar cells was demonstrated using the conventional mature industrial manufacturing process that is presently used for the amorphous silicon solar cells. To summarize, this research compares various post-transition metals as a catalyst for the growth of nanowires discussing their properties, and such silicon nanowires can be utilized in several other applications not only limited to photovoltaic research

In-situ catalyst mediated growth and self-doped silicon nanowires for use in nanowire solar cells

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.We report the growth of self-doped silicon nanowires (SiNWs), using gallium and bismuth catalysts, by employing a vapour-liquid-solid method. This enables the formation of both p- and n-doped nanowires without the use of expensive and toxic gases that are conventionally used and opens a new route to a simplified and cost effective process for doping SiNWs. The chosen catalysts have the lowest eutectic temperature available for the growth of silicon nanowires. The growth of self-doped SiNWs, for the fabrication of photovoltaic cells, has been demonstrated for the first time in this study

Biodiversity of the Adipocyte-Derived Hormone, Leptin

The adipocyte derived hormone leptin is known for its pivotal role in the regulation of a variety of physiological functions mainly associated with metabolism and energy homeostasis. One of the major functions of leptin is pertain with its angiogenic induction in support of organ development as well as under pathological conditions such as atherosclerosis and cancer. Leptin is a well-known pro-angiogenic growth factor which exerts its role through Ob-R receptor present on endothelial cells. The therapeutic application of leptin is based on its potential to maintain various functions at pathological conditions. In this book chapter, the multi-diversity potentials of leptin are discussed in detail

South Asian Economic Constitutionalism: A Path to Constitutional Order

South Asia is a region of diverse post-colonial countries that are undergoing significant constitutional and socioeconomic change. Constitutional law scholars have taken an interest in South Asian constitutionalism and how the region is addressing its unstable democratic systems. In recent years, South Asian states have amended or replaced their constitutions and forms of governance. Two recent crises, the 2021 Taliban offensive in Afghanistan and the 2022 Sri Lankan political crisis, highlight the importance of economic governance and the role of accountable government in the market. Despite constitutional structures for economic governance and the establishment of government institutions, South Asian states are witnessing the weakening of institutional mechanisms and the delegitimization of the rule of law. This paper argues that South Asian states need to develop practices that focus on accountable constitutional governance of the economy and strengthening financial institutions. While South Asian constitutions have traditionally kept economic actions by the state outside the purview of judicial and public scrutiny, the lack of accountability and the cynical manipulation of economic institutions by authoritarian leaders raises questions about the constitutional limits of the power of elected leaders. The paper explores how strengthening the pillars of economic constitutionalism can lead to the creation of a stable constitutional order in South Asia

A study of Selenium nanoparticles as Charge Storage Element for Flexible semi-transparent memory Devices

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Flexible Semi-Transparent electronic memory would be useful in coming years for integrated flexible transparent electronic devices. However, attaining such flexibility and semi-transparency leads to the boundaries in material composition. Thus, impeding processing speed and device performance. In this work, we present the use of inorganic stable selenium nanoparticles (Se-NPs) as a storage element and hydrogenated amorphous carbon (a-C:H) as an insulating layer in two terminal non-volatile physically flexible and semi-transparent capacitive memory devices (2T-NMDs). Furthermore, a-C:H films can be deposited at very low temperature (<40° C) on a variety of substrates (including many kinds of plastic substrates) by an industrial technique called Plasma Enhanced Chemical Vapour Deposition (PECVD) which is available in many existing fabrication labs. Self-assembled Se-NPs has several unique features including deposition at room temperature by simple vacuum thermal evaporation process without the need for further optimisation. This facilitates the fabrication of memory on a flexible substrate. Moreover, the memory behavior of the Se-NPs was found to be more distinct than those of the semiconductor and metal nanostructures due to higher work function compared to the commonly used semiconductor and metal species. The memory behavior was observed from the hysteresis of current-voltage (I–V) measurements while the two distinguishable electrical conductivity states (“0” and “1”) were studied by current-time (I-t) measurements

Stability of Hydrogenated Amorphous Carbon thin films for application in Electronic Devices

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.In this study, hydrogenated amorphous carbon (a-C:H) films are investigated for electronic applications as an insulating layer. a-C:H films were deposited using radio frequency-Plasma enhanced chemical vapour deposition (RF-PECVD) technique at room temperature. For the first time, the properties of a-C:H films as a function of annealing temperature is investigated, with a focus on their electrical and optical properties. This study shows that a-C:H films are stable up to 450ºC. This investigation will facilitate the use of a-C:H films as an insulating layer where the semiconductor active layers are deposited at higher temperatures (e.g. amorphous silicon deposited around 300ºC for thin film transistor TFTs). In addition to understanding the electrical and optical properties of annealed a-C:H films, we have further explored and studied its suitability in Flash-type memory devices. Various forms of diamond-like carbon are considered to have a high chemical resistance; no extensive data are available in the literature on this subject. The stability of a-C: H thin films with various reactive chemicals, commonly used in organic/printable electronic devices, is also investigated in this work. The findings may provide opportunities for adoption/integration of a-C:H in hybrid organic-inorganic electronic devices