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The factors that control the rate and selectivity of 4e

One of the major goals of bioinorganic chemistry has been to mimic the function of elegant metalloenzymes. Such functional modeling has been difficult to attain in solution, in particular, for reactions that require multiple protons and multiple electrons (

Orhan Pamuk’s The White Castle is a historical novel that is set during the Ottoman reign. The novel presents the metaphysical opposition of East and West, self and the other, intuition and reason, mysticism, science and global and local, and the recurring issues of conflict of civilization, identity crisis, and cultural variations. Orhan Pamuk as a postmodern writer tries to bridge the gap between the East and the West through his writings. Although Turkey is at the backdrop in most of his novels, the treatment of themes is universal. The paper proposes the theory of Orientalism by Edward Said, which represents the encounter and treatment of the "Orient." The concept of identity expressed by Pamuk in his wide range of novels also can be related to the “Orient” and “Occident.” The culture of the East has always been portrayed as the binary opposite of Europe in history and fiction. The loss of identity of the East reflected in the works of Pamuk is an outcome of the clash between East and Europe, further leading to chaotic contexts and dilemmatic protagonists. Individuals unable to choose between the traditional self and the fashionable West mourn the lost identity of a country and their self.

In this paper, a hierarchical virtual inertia control technique for a bidirectional DC–DC converter is proposed to enhance inertia of an isolated DC microgrid through the DC bus voltage regulation....

In this study, energy management and damping improvement of a DC microgrid are proposed by using an interconnection and damping assignment–passivity-based control (IDA–PBC) technique. The control technique is applied for (i) the grid connected inverter and (ii) the DC–DC converters connected with fuel cell and battery of the DC microgrid to control the DC bus voltage. The IDA–PBC generates the control laws with the desired energy function for the current controller of the converters based on the generation from the renewable power generators and load demand. In addition, an integral action is added with the IDA–PBC control laws to reduce the steady-state error in the DC bus voltage. The parameters of the IDA–PBC technique are tuned based on the state of charge of the battery and grid availability for a smooth transition between the operating modes and better energy management. It is proved that the derived energy function satisfies the Lyapunov stability criterion. Simulations are carried out in MATLAB/Simulink to test the performance of the proposed control technique. The results show that the proposed technique provides the desired damping and energy management.

In-operando spectroscopic observation of the intermediates formed during various electrocatalytic oxidation and reduction reactions is crucial to propose the mechanism of the corresponding reaction. Surface-enhanced resonance Raman spectroscopy coupled to rotating disk electrochemistry (SERRS-RDE), developed about a decade ago, proved to be an excellent spectroscopic tool to investigate the mechanism of heterogeneous oxygen reduction reaction (ORR) catalyzed by synthetic iron porphyrin complexes under steady-state conditions in water. The information about the formation of the intermediates accumulated during the course of the reaction at the electrode interface helped to develop better ORR catalysts with second sphere residues in the porphyrin rings. To date, the application of this SERRS-RDE setup is limited to ORR only because the thiol self-assembled monolayer (SAM)-modified Ag electrode, used as the working electrode in these experiments, suffers from stability issues at more cathodic and anodic potential, where H2O oxidation, CO2 reduction, and H+ reduction reactions occur. The current investigation shows the development of a second-generation SERRS-RDE setup consisting of an Ag nanostructure (AgNS)-modified graphite electrode as the working electrode. These electrodes show higher stability (compared to the conventional thiol SAM-modified Ag electrode) upon exposure to very high cathodic and anodic potential with a good signal-to-noise ratio in the Raman spectra. The behavior of this modified electrode toward ORR is found to be the same as the SAM-modified Ag electrode, and the same ORR intermediates are observed during electrochemical ORR. At higher cathodic potential, the signatures of Fe(0) porphyrin, an important intermediate in H+ and CO2 reduction reactions, was observed at the electrode–water interface.

Unique observational features of a convective cluster, occurred on 12-Sept-2015, over the rain shadow region in the leeward side of Western Ghats have been presented in this study. The synoptic environment had preconditioned the formation of a convergence zone over the study area. Moisture transport from the Arabian Sea was responsible for the moistening in the lower layers. Boundary layer convective thermals contributed to middle level moistening and subsequent onset of the cloud cluster was accompanied by a sudden surge of moist and warm air into the middle troposphere, and subsequent lifting of freezing level (FL) and wet bulb temperature zero (WBT0) levels. Sudden changes in the FL and WBT0 levels in association with the gust front prior to the initiation of the cloud system has been documented with high-resolution measurements using microwave radiometer and wind profiler. Thermodynamical parameters from radiometer illustrate the percussive conditions for formation of the cloud system. The cloud cluster had resulted in 25.50 mm rainfall, attributing to ~ 91% of convective rain. Intense fall velocity (10–12 ms−1) was noted up to ~ 7 km during the convective rain and the fall velocity was reduced to ~ 7 ms−1 (below the melting layer) during the stratiform counterpart. The cloud system was forecasted using WRF model (version 3.6.1), which was reproduced reasonably well as in the observations and the model output has been analyzed to understand the morphology of the system. The features such as formation of a cold pool, initiation of convective rainfall from the system were well forecasted by the model. Microphysical characteristics of the cloud cluster have also been examined. Riming was the dominant microphysical process within the convective regime. A major contribution to precipitation was from melting of ice hydrometeors especially graupel and snow was noted. Deep warm layer and associated production of supercooled liquid by the lifting of liquid water above the freezing level in updrafts exceeding 15 ms−1 was important for the production of a mixed-phase cloud system. Vapor deposition and aggregation process was noted in the stratiform/anvil counterpart, which also contained mixed phase hydrometeors, primarily of snow.

The use of inertia emulation in a microgrid has been growing as a promising control approach to maintain the bus voltage and frequency. An inertia emulation-based control technique is proposed for a DC microgrid supplying AC loads in this study. The proposed work includes: (i) the DC bus voltage regulation using virtual inertia control and economic power management by a current sharing algorithm in cascade with a restoration control; (ii) AC load bus voltage and frequency regulation using virtual excitation emulation and inertia emulated control that utilises the emulated inertia and DC bus voltage. Further, it also provides inertia support to the grid. The coordinated current sharing algorithm manages the current (power) sharing between the grid and battery pack of electric vehicles based on electricity price and state of charge of the battery. The cascaded restoration control eliminates the steady-state error in the DC bus voltage. Finally, the DC microgrid is simulated under various operating conditions to verify the performance of the proposed control approach. The simulation results reveal that the objectives are achieved successfully.

In this paper, a deloading control technique is proposed for a photovoltaic system to regulate DC link voltage under lightly loaded conditions. A simplified deloading control technique that can regulate the DC link voltage is proposed here for the battery bank supported PV system. In addition, the proposed control technique is implemented in field-programmable gate array (FPGA)-in-loop simulation to verify the feasibility of successful hardware implementation. The proposed controller is converted into an equivalent code in VHDL, a hardware description language. In the implementation process, the code is implemented in Zedboard (FPGA hardware), which is interfaced with MATLAB/Simulink and Vivado software. The results obtained using the FPGA-in-Loop simulation are satisfactory and maintaining the DC link voltage within the limit under both MPPT and deloading conditions.

Proper detection of islanding of a microgrid and its resynchronisation is very important for the plug and play operation. A simple passive islanding detection and resynchronisation technique is proposed in this paper. The change in the voltage magnitude, frequency and phase are taken into the consideration to avoid any false triggering during the detection process. In addition, the proposed technique is designed in such a way that it can be implemented in a field-programmable gate array (FPGA) hardware using FPGA-in-Loop (FIL) platform. The complete controller is converted into VHDL, a hardware description language code. Finally, the bitstream generated from the code is implemented in FPGA hardware, Zedboard. The results obtained in terms of both islanding detection and resynchronisation using the FPGA-in-Loop simulation are found to be satisfactory.

In this paper, a solar-PV and wind energy based grid connected hybrid system and its associated control schemes are presented to study the system dynamic responses at varying wind velocity and solar irradiation. Maximum power point tracker (MPPT) and blade pitch angle control algorithms are incorporated to capture maximum wind and solar power, and also to limit the wind energy to its rated value when wind speed is beyond its rated respectively. Voltage (stator and grid) oriented vector control (VOVC) schemes are utilized (i) to achieve variable speed constant frequency (VSCF) operation, (ii) to get the control of active and reactive powers independently and (iii) to operate the system at unity power factor (UPF). The system is implemented in MATLAB/Simulink environment and its performances are studied thoroughly. Result shows that the system is properly working and also gives very good dynamic responses at variation of input sources (solar and wind).

In a DC microgrid (DCMG), the DC bus voltage is vulnerable to the power fluctuations caused by the variations of intermittent renewable energy sources and local loads. A concept is developed to operate a bidirectional DC-DC converter as a DC machine to mimic the inertia characteristic of a DC machine and regulate the DC bus voltage fluctuations during power fluctuations of the DCMG. The concept of operating a bidirectional DC-DC converter as a DC machine can be termed as virtual DC machine (VDCM). The proposed concept of a VDCM is basically a control technique for a bidirectional DC-DC converter, which is derived from the theory of the DC machine operation and its speed control technique. The implementation, operation, controller design and dynamics of VDCM are also discussed. A VDCM can be easily operated in both generating and motoring mode also. Being free from comparatively slower mechanical devices, a VDCM can switch over from one mode to another very quickly. Hence, it provides a useful way to control the storage devices in microgrid applications.

The performance of three microphysics schemes (WRF Double Moment 6-class (WDM6), Morrison double moment (MORR), and spectral bin microphysics (Fast version) (SBMF)), with increasing complexities, in simulating various rainfall-types during the lifecycle of a tropical continental mesoscale cloud cluster (CC) are presented in this study. The CC spent its entire lifetime over the surveillance area of a polarimetric C-band radar, over the peninsular Indian region in a monsoon environment. Observed and simulated rainfall properties throughout the lifecycle of the CC are intercompared. A rainfall-type categorization algorithm has been applied to the observed and model simulated reflectivity fields. Microphysics scheme with the least complexities produced the highest convective rainfall-type, lowest stratiform rainfall-type, and a remarkable early cessation of the CC. With increasing complexities, the microphysics schemes are found to represent the rainfall-types more close to radar observations. Major differences are noted during the mature and dissipation phases, especially in the stratiform rainfall-type. The rainfall-types derived from radar, as well as three simulations with WDM6, MORR, and SBMF schemes, showed ~18%, ~54%, ~41%, and ~29% of convective rainfall fraction (including isolated convective categories), ~14%, ~33%, ~18%, and ~20% of mixed rainfall fraction and ~68%, ~13%, ~42%, and ~50% of stratiform rainfall fraction respectively during the lifecycle of the CC. The accumulated rainfall derived from radar observations, using a blended rainfall estimation algorithm, indicated substantial differences in the observed and simulated rainfall pattern. The lower moment scheme has a tendency to produce more lighter as well as heavy rainfall compared to the higher moment schemes.

The paper presents an interconnection damping assignment - passivity based control (IDA-PBC) strategy applied to a grid-connected inverter interfaced Photovoltaic (PV) system. The PV power plant is integrated to the grid using a pulse-width-modulated converter. This is done to extract maximum energy from the renewable resource and feed it to the grid. The main contribution of this paper is to design a nonlinear control law based on IDA-PBC with a desired energy function along with an integral action. In the design of IDA-PBC, the Hamiltonian function is considered as a Lyapunov function candidate for analysing the stability criteria. In this paper, a step by step design procedure of the IDA-PBC is presented and the performance of the controller is compared with a conventional PI-based controller. A simulation study of the system is carried out in Matlab/Simulink environment. Finally, the simulation results show that the IDA-PBC with an integral action performs better during both transient and steady state conditions as compared with the PI-based controller.

An extreme rainfall event that made major calamity over the Indian peninsula region has been investigated with a focus on the physics of the cloud system as indicated from the multi-satellite observations, ground-based radar, and model forecast experiments. The vertical structure of clouds showed deep convective cores embedded in the stratiform and is dominated by warm and mixed-phase clouds. Model output indicates that moisture convergence was present in two episodes before both heavy rainfall events, and can be used as a precursor for the imminent heavy rainfall. It is the sustenance of high winds and availability of moisture content that contributed to the development of deep convective cloud bands which propagated inland, perpendicular to the coastline. These cloud systems produced deep convective cores with a deep supersaturated layer throughout the middle and upper atmosphere, introduced a significant amount of supercooled liquid water, which facilitated mixed-phase clouds. These cloud liquid drops at supercooled temperatures facilitated the production of more ice hydrometeors on freezing. The rapid growth of hydrometeors through riming and aggregation in the mixed-phase region lead to heavy and sustained precipitation. The sustenance of the system is also due to the enhanced latent heating over Western Ghats that supported low-level moisture convergence in a strongly sheared environment. Documented evidence from this study suggests that the heavy precipitation was a result of the convective cluster as illustrated through satellite observations and numerical simulations.

article Functional studies have shown that the sphingolipid ceramide, self-assembles in phospholipid membranes to form large channels capable of allowing proteins to cross the membrane. Here these channels are visualized by negative stain transmission electron microscopy. The images contain features consistent with stain-filled pores having a roughly circular profile. There is no indication of tilt, and the results are consistent with the formation of right cylinders. The sizes of the pores range from 5 to 40 nm in diameter with an asymmetric distribution indicating no apparent upper size limit. The size distribution matches well with the distribution of sizes calculated from electrophysiological measurements.

The effect of pepsin digestion on the allergenicity of raw and thermally processed (boiled and fried) fish muscle extracts of two widely consumed fishes bhetki (Lates calcarifer) and mackerel (Rastrelliger kanagurta) was studied. Sere were collected from 110 patients who were hypersensitive to fish, as evidenced by their clinical history, symptoms and positive skin-prick test results. The various extracts after digestion with pepsin at different times of incubation were tested for specific IgE-binding activity by ELISA and immunoblotting with patients' sera. All the extracts of both the fishes retained their allergenicity as evidenced by ELISA and immunoblotting. In bhetki, maximum allergenicity was found in the pepsin-digested fried extract, whereas similar treatment decreased the allergenicity in fried mackerel. Results showed that raw as well as thermally processed allergens of both the fishes maintained strong allergenicity, even after digestion with pepsin for different time periods. The study revealed that the fish proteins played an important role in manifestation of allergy, due to their stable structure, which was retained even after pepsin and heat treatment.

Fluctuations in ionic strength have been documented in apoptosis. While the exact molecular identity of the channels through which proteins permeate across the outer mitochondrial membrane is unclear, it is fairly certain that the channel is large in size and sustained over time. We sought to determine the effect of salt concentration on Bax and tBid in inducing MOMP. While high salt buffer (60mM) facilitated more release of inter-membrane space (IMS) proteins (Adenylate Kinase and Sulfite Oxidase) with Bax and tBid than low salt (5mM HEPES buffer), low salt conditions induced more sustained, real-time permeabilization, as measured by accessibility of exogenous cytochrome c to complex IV. There was a dichotomy between the kinetics of IMS protein release and real-time permeabilization at high salt conditions, while under low salt conditions, they were congruent. The effect of ionic strength on sustained permeabilization is biphasic, with maxima at 10mM. The sustained permeabilization is inducible by diluting the salt concentration to that of low salt, but irreversible by incorporating high salt conditions. This observation is inconsistent with a dynamic channel model sensitive to ionic strength. It seems likely that under low salt conditions, there is a co-operative interaction between Bax molecules in the membrane and those in solution, but the growth of the channel by membrane-bound Bax molecules itself is independent of ionic strength. Supported by a grant from NSF (MCB-0641208).