Concentration of CO<SUB>2</SUB> over melting ice oscillates

We report that the concentration of CO2 over melting ice oscillates as long as water and ice coexist. A phenomenological model involving melting of CO2 containing ice leading to its release, readsorption of the vapor on ice, and dissolution in water is proposed. Thermokinetics of these processes lead to nonlinearity of the dynamics. This phenomenon is also observed over impure ice contaminated with salts or in the presence of nitrogen or air. Oscillations have been observed in several other solute or ice-water systems

Secure Communication Model for Dynamic Task Offloading in Multi-Cloud Environment

As the data is increasing day-by-day, the mobile device storage space is not sufficient to store the complete information and also the computation capacity also is a limited resource which is not sufficient for performing all the required computations. Hence, cloud computing technology is used to overcome these limitations of the mobile device. But security is the main concern in the cloud server. Hence, secure communication model for dynamic task offloading in multi-cloud environment is proposed in this paper. Cloudlet also is used in this model. Triple DES with 2 keys is used during the communication process between the mobile device and cloudlet. Triple DES with 3 keys is used by the cloudlet while offloading the data to cloud server. AES is used by the mobile device while offloading the data to the cloud server. Computation time, communication time, average running time, and energy consumed by the mobile device are the parameters which are used to evaluate the performance of the proposed system, SCM_DTO. The performance of the proposed system, SCM_DTO is compared with ECDH-SAHE and is proved to be performing better

Oxygen Activation and Radical Transformations in Heme Proteins and Metalloporphyrins

As a result of the adaptation of life to an aerobic environment, nature has evolved a panoply of metalloproteins for oxidative metabolism and protection against reactive oxygen species. Despite the diverse structures and functions of these proteins, they share common mechanistic grounds. An open-shell transition metal like iron or copper is employed to interact with O_2 and its derived intermediates such as hydrogen peroxide to afford a variety of metal–oxygen intermediates. These reactive intermediates, including metal-superoxo, -(hydro)peroxo, and high-valent metal–oxo species, are the basis for the various biological functions of O_2-utilizing metalloproteins. Collectively, these processes are called oxygen activation. Much of our understanding of the reactivity of these reactive intermediates has come from the study of heme-containing proteins and related metalloporphyrin compounds. These studies not only have deepened our understanding of various functions of heme proteins, such as O2 storage and transport, degradation of reactive oxygen species, redox signaling, and biological oxygenation, etc., but also have driven the development of bioinorganic chemistry and biomimetic catalysis. In this review, we survey the range of O_2 activation processes mediated by heme proteins and model compounds with a focus on recent progress in the characterization and reactivity of important iron–oxygen intermediates. Representative reactions initiated by these reactive intermediates as well as some context from prior decades will also be presented. We will discuss the fundamental mechanistic features of these transformations and delineate the underlying structural and electronic factors that contribute to the spectrum of reactivities that has been observed in nature as well as those that have been invented using these paradigms. Given the recent developments in biocatalysis for non-natural chemistries and the renaissance of radical chemistry in organic synthesis, we envision that new enzymatic and synthetic transformations will emerge based on the radical processes mediated by metalloproteins and their synthetic analogs

Wireless Pressure Sensor Using Non-contact Differential Variable Reluctance Transducer

A diaphragm based wireless pressure sensor using a non-contact differential variable reluctance transducer (NC-DVRT) is developed. A NC-DVRT senses the micro displacements of a diaphragm and operates by detecting the change in reluctance of a sense coil with respect to a compensation coil, when brought in close proximity to a highly conductive material. In the present work, a stainless steel (SS) diaphragm was used as a pressure port and a commercial NC-DVRT was fixed behind it at a distance of 140 μm. Output of the NC-DVRT was digitized using PSoC microcontroller and was transmitted using a wireless RF module. The developed pressure sensor can measure the positional movement of the SS diaphragm in both the directions with an accuracy of 2 μm corresponding to a pressure of 0.1 bar and communicate to a remote PC

Dielectric and ferroelectric properties of multicomponent equiatomic calcium lead strontium titanate (Ca0.33Pb0.33Sr0.33)TiO3

Perovskite oxides are well-known for their dielectric and ferroelectric properties. In this work, the dielectric properties of calcium lead strontium titanate synthesized by reverse co-precipitation process with two different solvent concentrations were studied. Formation of single phase was confirmed by X-ray diffraction and tetragonality present in the lattice was analysed through Rietveld refinement. The grain size, morphology and composition were studied using scanning electron microscope and energy dispersive spectroscopy. The influence of frequency in the range of 1 ​Hz–107 ​Hz and temperature range -100 ​°C to 300 ​°C on dielectric response were studied. Curie-Weiss fits showed both the systems to be relaxor ferroelectrics. The dielectric relaxation mechanism and activation energy were determined from the electric modulus. The relaxation time and the dissipation factors were obtained from Cole-Cole analysis. The ferroelectric properties were assessed using a polarization-electric field loop tracer and efficiencies of memory storage were analysed

Nutritional status of cancer patients given different treatment modalities

The nutritional status of 91 cancer patients was assessed at the time of diagnosis and follow-up assessments were carried out at the third and sixth week after initiating different treatment modalities to study the effect of type and duration of treatment on nutritional status. Parameters assessed were anthropometry, biochemical status and clinical signs and symptoms of nutritional deficiencies. Treatment modalities studied were radiotherapy, chemotherapy, chemotherapy+radiotherapy, and combined treatment modality (surgery+radiotherapy+chemotherapy). The nutritional status of male patients was affected most by chemotherapy+radiotherapy while females were affected most with radiotherapy. Biochemical parameters showed a marginal decline in total serum protein and serum albumin concentrations. Haemoglobin concentrations declined substantially with radiotherapy and chemotherapy. The lymphocyte count decreased substantially irrespective of the treatment modality. Clinical examination revealed increased incidences of deficiency signs and symptoms in all patients during follow-up irrespective of treatment modality