DG Incorporation Research Articles

A New Framework for Active Loss Reduction and Voltage Profile Enhancement in a Distributed Generation-Dominated Radial Distribution Network

In recent times, a significant amount of power loss and system instability due to high voltage deviation experienced by modern power systems, in addition to the pressing issues challenging the power industry such as pollution—especially the emission of greenhouse gases—and aging infrastructures, have posed a serious threat to system operations. Distributed generation has been identified as one main solution capable of reducing pollution when solar and wind power are used and, hence, rejuvenating dilapidated infrastructures and redeeming climatic changes. This paper presents a novel two-stage approach for the identification of suitable locations for DG placement and the sizing of DG for loss reduction and voltage stability enhancement. The first stage explored the use of a network structure to develop a coupling factor (CF) approach that was non-iterative in nature to determine suitable DG locations. In the second stage, the size of the DG was determined using the particle swarm optimization (PSO) algorithm. The main objective was to obtain an optimal voltage profile of the system under consideration while lowering the power loss in the system and ensuring network stability amidst DG incorporation. The model design, optimization and simulation were carried out using the MATLAB 2016a environment and the IEEE 33-bus test system, in which DG was integrated. The influence of increasing the level of DG placement in the system was then investigated. The forward/backward sweep method was applied to monitor the optimization process. The voltage profiles for both the base case when no DG was integrated and the case of incremental DG integration were considered. The results obtained for both single and multiple DG integration are compared with those obtained using the existing methods. The results show the efficiency and applicability of the new non-iterative scheme in the quick identification of DG locations for voltage profile enhancement and network real power loss reduction in radial distribution networks.

Bi-objective robust optimization for reliability-oriented power network planning by considering distributed generation effects: A case study in Iran

In the present study, a new mixed-integer linear programming is presented for a reliability-oriented power network. The reliability approach is conducted using the Average Energy Not Supplied (AENS) index and System Average Interruption Duration Index (SAIDI) based on the feeder’s failure rate. In this formulation, the constraints include standard ranges for electric power and current magnitude, acceptable voltage drop, power law, and power balance considering loss power. Moreover, the relation between feeder failure rate and electric power level and subsequently SAIDI for outage duration control is added in constraints to improve network reliability. The model is studied on a real case study in Iran in two scenarios with or without considering DG. The obtained results indicate that optimization for DG location and its capacity in the power system decrease AENS cost. Furthermore, DG incorporation in the grid reduces load congestion in substations and system’ total cost. Augmented Epsilon Constraint (AEC) method is utilized to solve two-objective mixed-integer linear programming. To overcome the uncertain environment, the robust optimization is applied, and the effect of Γ parameters is investigated on Pareto sets and system’s total costs. As confirmed by numerical results, by increasing demand constraint conservative level, the objective function gets away from the nominal value, requiring that Decision-Makers create an appropriate balance between conservative levels and system costs. The obtained results reveal the efficiency and effectiveness of the proposed mathematical model in the real world. • New reliability-oriented multi stage power network planning. • Determination the feeders failure rates via power storage and AENS cost. • Considering uncertainty in demand forecasting and facility installation costs. • DG incorporation as a facility to costs reduction and reliability reinforcement.

Implication of DG Incorporation in Criticality Assessment of Power Network Buses Using Betweenness Metric

Implication of DG Incorporation in Criticality Assessment of Power Network Buses Using Betweenness Metric

DNA Polymerase V Kinetics Support the Instructive Nature of an Oxidized Abasic Lesion in Escherichia coli

Translesion synthesis past an oxidized abasic site, 2-deoxyribonolactone, in Escherichia coli results in high levels of dG incorporation and is dependent upon DNA polymerase V (Pol V). Kinetic experiments performed here affirm that Pol V preferentially incorporates dG opposite 2-deoxyribonolactone (L). Pol V discriminates between dG and dA on the basis of the apparent KD, suggesting that L provides instructive structural information to the enzyme despite lacking a Watson-Crick base.

Hydrogen Bonding Contributes to the Selectivity of Nucleotide Incorporation Opposite an Oxidized Abasic Lesion

The ability of DNA polymerases to maintain the integrity of the genome even after it has been structurally altered is vital. There is considerable interest in determining the structural properties of the DNA template that polymerases recognize when determining which nucleotide to add to a nascent strand. Mechanistic, synthetic, and structural chemistries have been used to study how DNA polymerase activity is affected by size, shape, pi-stacking, and hydrogen bonds of the template molecules. Herein, we probe the structural aspects of abasic lesions that result in their distinct coding potential in Escherichia coli despite lacking a Watson-Crick base. In particular, we investigate why bypass of 2-deoxyribonolactone (L) results in significant amounts of dG incorporation opposite the lesion, whereas other abasic lesions (e.g., AP) adhere to the "A-rule". Experiments using synthetic analogues reveal that DNA polymerase V bypasses L and increased levels of dG incorporation result from a hydrogen bonding interaction between the carbonyl oxygen and dG. These results show that a DNA polymerase utilizes hydrogen bonding as one structural parameter when decoding an abasic lesion.

In vitro inhibition of hepadnavirus polymerases by the triphosphates of BMS-200475 and lobucavir.

The guanosine analogs BMS-200475 and lobucavir have previously been shown to effectively suppress propagation of the human hepatitis B virus (HBV) and woodchuck hepatitis virus (WHV) in 2.2.15 liver cells and in the woodchuck animal model system, respectively. This repression was presumed to occur via inhibition of the viral polymerase (Pol) by the triphosphate (TP) forms of BMS-200475 and lobucavir which are both produced in mammalian cells. To determine the exact mode of action, BMS-200475-TP and lobucavir-TP, along with several other guanosine analog-TPs and lamivudine-TP were tested against the HBV, WHV, and duck hepatitis B virus (DHBV) polymerases in vitro. Estimates of the 50% inhibitory concentrations revealed that BMS-200475-TP and lobucavir-TP inhibited HBV, WHV, and DHBV Pol comparably and were superior to the other nucleoside-TPs tested. More importantly, both analogs blocked the three distinct phases of hepadnaviral replication: priming, reverse transcription, and DNA-dependent DNA synthesis. These data suggest that the modest potency of lobucavir in 2.2.15 cells may be the result of poor phosphorylation in vivo. Kinetic studies revealed that BMS-200475-TP and lobucavir-TP competitively inhibit HBV Pol and WHV Pol with respect to the natural dGTP substrate and that both drugs appear to bind to Pol with very high affinities. Endogenous sequencing reactions conducted in replicative HBV nucleocapsids suggested that BMS-200475-TP and lobucavir-TP are nonobligate chain terminators that stall Pol at sites that are distinct yet characteristically two to three residues downstream from dG incorporation sites.

Reiterative dG addition by Euplotes crassus telomerase during extension of non-telomeric DNA.

Telomerase from the ciliate Euplotes crassus incorporates G4T4telomeric repeats onto both telomeric and non-telomeric single-stranded DNA 3'-ends via reverse transcription of a templating domain in its RNA subunit. Here we describe an unusual mode of template copying that is characteristic of DNA synthesis onto non-telomeric 3'-ends in vitro . When dTTP was eliminated from telomerase reactions, telomeric primers or DNA products generated from the telomerase endonuclease were extended by precise copying of the RNA template. In contrast, telomerase catalyzed the addition of up to 13 dG residues onto primers with non-telomeric 3'-ends under the same reaction conditions. Introducing mismatches in the 3'-terminus of telomeric primers that reduced primer complementarity to the RNA template induced reiterative dG incorporation, indicating that the reaction is influenced by Watson-Crick base pair formation between the primer and the RNA template. Unexpectedly, the reiterative dG addition mode was confined to telomerase derived from developing cells that undergo new telomere formation. This reaction was not observed in vegetatively growing cells. We postulate that indiscriminate dG addition by telomerase occurs by reiterative copying of C residues in the telomerase RNA templating domain and reflects lateral instability of the primer-template interaction during de novo telomere formation.

Incorporation of 2-deoxy- d-glucose into glycogen. Implications for measurement of tissue-specific glucose uptake and utilisation

Estimation of glucose uptake in vivo using 2-deoxy- d-[2,6- 3H]glucose (2DG) relies upon the assumption that the phosphorylated form, 2-deoxy- d-[2,6- 3H]glucose 6-phosphate (2DGP), cannot be further metabolised. We aimed to determine whether this assumption leads to under-estimation of glucose uptake due to the incorporation of 2DGP into glycogen. Rats were infused with [U- 14C]glucose and 2-[ 3H]DG, and the incorporation into glycogen was measured. These were compared to the accumulation of 2-[ 3H]DGP in heart, liver, muscle, white adipose tissue and brown adipose tissue. 2DG was incorporated into glycogen in an insulin-dependant manner (e.g. in soleus, at basal, physiological and supraphysiological insulin concentrations, glycogen synthesis rates from 2DG were 17.81 ± 3.07, 64.47 ± 7.47 and 203.23 ± 44.52 nmol glucose incorporated/g min −1, respectively). The rate of glycogen synthesis from 2-[ 3H]DG was identical to that for [U- 14C]glucose in all tissues studied except for heart and brown adipose tissue (e.g. in soleus at physiological insulin concentration, 2-[ 3H]DG incorporation was 64.47 ± 7.47 and [U- 14C]glucose incorporation was 61.87 ± 7.56 nmol glucose/g min −1). Furthermore, the proportion of 2DG incorporated into glycogen was significant with respect to total glucose uptake at all plasma insulin concentrations (10.7% ± 0.9, 14.0% ± 1.9 and 25.6% ± 5.6 at basal, physiological and supraphysiological insulin concentrations, respectively). 2DG was metabolised to glycogen in all tissues studied causing an underestimation of the rate of glucose uptake by measurement of 2DGP accumulation alone. In addition, use of 2DG could provide a method for assessing the rate of direct glycogen synthesis in the rat.

Changes in [ 14C]deoxyglucose incorporation into rat brain regions during heat-seeking behavior in the cold environment

The central nervous structures involved in behavioral thermoregulatory responses during cold exposure were investigated in conscious rats by means of the 2-deoxy-D-[ 14C]glucose ([ 14C]-DG) autoradiographic technique. According to autoradiographs, many brain regions with significant increases or decreases in [ 14C]-DG incorporation were observed during thermoregulatory behavior. When animals were only exposed to cold, significant increases in [ 14C]-DG incorporation were observed in the caudate putamen, lateral preoptic area, medial forebrain bundle, ventromedial hypothalamus (VMH), posterior hypothalamus, ventroposteromedial thalamus (VPM), dorsomedial thalamus (MD), substantia nigra (SN) and red nucleus (RN). Lower activities were observed in the hippocampus and the medial habenula. However, when animals performed the behavioral thermoregulation (heat seeking behavior) significant increases were noted in the sulcal prefrontal cortex, sensory-motor cortex, and MD, while decreases were noted in the piriform cortex, VMH, VPM, medial habenula, SN and RN, compared with those in the group without the thermoregulatory behavior.

Astrocyte opioid receptors: Activation modifies the noradrenaline-evoked increase in 2-[ 14C]deoxyglucose incorporation into glycogen

Astrocyte-enriched cultures of the newborn rat cortex accumulated 2-[ 14C]deoxyglucose (2-DG), a proportion of which was incorporated into glycogen. Exposure to exogenous noradrenaline resulted in an increase (30%) in the incorporation of 2-[ 14C]DG into glycogen in these cultures. The extent to which noradrenaline evoked an increase in 2-[ 14C]DG labelling of glycogen was modified by both morphine and methionine-enkephalin. Whereas morphine augmented the noradrenaline-induced increase in 2-[ 14C]DG incorporation into glycogen in these cultures, methionine-enkephalin attenuated this response.

14C]deoxyglucose incorporation into rat brain regions during hypothalamic or peripheral thermal stimulation.

The central nervous structures involved in thermoregulatory responses induced by hypothalamic or peripheral thermal stimulation were investigated in conscious rats by means of the 2-deoxy-D-[14C]glucose ([14C]-DG) autoradiographic technique. According to autoradiographs, many brain regions with significant increases or decreases in [14C]-DG incorporation were observed during thermoregulatory responses. Based on the present changes in [14C]-DG incorporation of brain regions obtained from two kinds of thermal stimulation, the following conclusions were drawn. 1) The medial preoptic area and the medial forebrain bundle are common sites for development of thermoregulatory responses being activated during cooling and warming. 2) The anterior hypothalamic area is activated during hypothalamic or peripheral warming and not during cooling. 3) The ventromedial hypothalamus, dorsomedial thalamus, caudate-putamen, globus pallidus, pars compacta of the substantia nigra, red nucleus, and the midbrain reticular formation are activated with hypothalamic or peripheral cooling. 4) The lateral preoptic area, suprachiasmatic nucleus, ventroposteromedial thalamus, pars reticulata of the substantia nigra, and the hippocampus change their activities only during peripheral cooling and warming.

Activation of brain regions in rats during food-intake operant behavior

The central nervous structures involved in bar pressing and feeding behavior during food-intake operant behavior were investigated in rats by the [ 14C]-deoxyglucose ([ 14C]-DG) autoradiographic technique. During bar pressing behavior, the [ 14C]-DG incorporation increased in the sensory-motor cortex, ventromedial thalamus, zona incerta, pars reticulata of substantia nigra, ligular cortex of the cerebellum and the reticular formation of the medulla. On the other hand, an increase of the [ 14C]-DG incorporation induced by feeding behavior was observed in the fornix, medial forebrain bundle, parietal cortex, trigeminal nuclei and the solitary nuclei.

Application of the 2-deoxy-(1-14C) glucose method to the study of suprachiasmatic nucleus activity and functions: phasic luteinizing hormone secretion and serotonin innervation.

A semi-quantitative analysis of 2-deoxy-(1-14C) glucose (2 DG) incorporation in the suprachiasmatic nucleus (SCN) was performed in male, castrated female, and castrated oestradiol treated female rats (OVX-E2) during the light period (from 9.00 h to 18.00 h). Unilateral orbital enucleation was carried out on each group. In males and castrated females the 2 DG incorporation in the rostral and caudal SCN was constant throughout the studied period. On the contrary, in OVX-E2 rats, which display a clear cut circadian rhythm of LH secretion, the 2 DG incorporation in the rostral SCN was higher in the afternoon than in the morning. After serotonin (5 HT) depletion, the level of morning labelling reached that of the afternoon. These results suggest the existence of a steroid-linked rhythm of SCN metabolic activity during the light period which might be related to the LH surge and dependent on 5 HT innervation.