Generation Of Sr Research Articles

Affinity Purification-Mass Spectrometry and Single Fiber Physiology/Proteomics Reveals Mechanistic Insights of C18ORF25.

C18ORF25 was recently shown to be phosphorylated at S67 by AMP-activated protein kinase (AMPK) in the skeletal muscle, following acute exercise in humans. Phosphorylation was shown to improve the ex vivo skeletal muscle contractile function in mice, but our understanding of the molecular mechanisms is incomplete. Here, we profiled the interactome of C18ORF25 in mouse myotubes using affinity purification coupled to mass spectrometry. This analysis included an investigation of AMPK-dependent and S67-dependent protein/protein interactions. Several nucleocytoplasmic and contractile-associated proteins were identified, which revealed a subset of GTPases that associate with C18ORF25 in an AMPK- and S67 phosphorylation-dependent manner. We confirmed that C18ORF25 is localized to the nucleus and the contractile apparatus in the skeletal muscle. Mice lacking C18Orf25 display defects in calcium handling specifically in fast-twitch muscle fibers. To investigate these mechanisms, we developed an integrated single fiber physiology and single fiber proteomic platform. The approach enabled a detailed assessment of various steps in the excitation-contraction pathway including SR calcium handling and force generation, followed by paired single fiber proteomic analysis. This enabled us to identify >700 protein/phenotype associations and 36 fiber-type specific differences, following loss of C18Orf25. Taken together, our data provide unique insights into the function of C18ORF25 and its role in skeletal muscle physiology.

Abstract P3191: Hur Mediates Calcium-driven Thermogenesis In Brown Adipose Tissue

Since the discovery of brown adipose tissue (BAT) in adult humans, its high energy capacity has driven investigations targeting adipose tissue thermogenesis as a supplement to whole-body energy expenditure to mitigate the energy imbalances observed in obesity. Uncoupling protein 1 (UCP1) is the primary driver of thermogenesis, however several additional UCP1-independent pathways have been identified. We previously reported that adipocyte deletion of the RNA binding protein human antigen R (HuR) results in thermogenic dysfunction independent of UCP1. RNA sequencing revealed the downregulation of several genes involved in calcium ion transport upon HuR deletion. Although recently established as a thermogenic mechanism in beige adipocytes, the effects of calcium-mediated thermogenesis in brown fat and its contribution to whole-body metabolism remain unexplored. Therefore, we set out to investigate the impact and regulatory mechanism of HuR on SR calcium cycling and heat generation in BAT. We hypothesize that HuR regulates thermogenesis in brown adipose tissue through control of RyR-mediated SR calcium release and assessed this experimentally using murine models with a BAT-specific deletion of HuR. Brown adipocytes isolated from BAT-HuR -/- mice were imaged for cytosolic calcium and heat using Fluo-4 calcium indicator and ERthermAC dye respectively. Cohorts of mice were also subjected to acute cold challenge or placed on a 12-week high fat diet study to assess whole-body thermal and energy metabolism. We now show that loss of HuR decreases adrenergic-stimulated calcium release and heat generation in brown adipose tissue, and that this effect is rescued by pharmacological stabilization of RyR2. We also report that HuR directly binds RyR2 mRNA in vivo and loss of HuR reduces RyR2 mRNA transcript stability. In assessing whole-body metabolism, we observed impaired thermal tolerance of BAT-HuR -/- mice from controls, as well as sex-dependent effects on diet-induced weight gain between models. Our findings reveal, for the first time, that brown adipocytes participate in calcium-mediated thermogenesis and identify a regulatory role for HuR in coordinating heat production through maintenance of RyR2 calcium release activity.

Plutonic-subvolcanic connection of the Himalayan leucogranites: Insights from the Eocene Lhunze complex, southern Tibet

The Lhunze region of southeast Tibet uniquely juxtaposes Cenozoic granitic plutons with subvolcanic rocks in the Tethyan Himalayan Sequence. In this study, the potential petrogenetic connection between two-mica granite and subvolcanic rhyolite porphyry from the Lhunze area is investigated using petrology, geochronology, and geochemistry. Monazite Th Pb ages imply the two-mica granite crystallized during the mid-Eocene at c. 43.5–43.1 Ma, consistent with previous zircon U Pb isotope data. Monazite in the porphyry also records Th Pb ages of c. 44.5–42.9 Ma , suggesting contemporaneous emplacement with the two-mica granite. Porphyritic structure, feldspar aggregates and comb alignment demonstrate that the two-mica granite resulted from transient melt flow associated with melt extraction. Some plagioclase phenocrysts from the porphyry have consistent An contents with the two-mica granite, indicating that both the two-mica granite and the porphyry probably originated from a similar melt. However, the porphyry has a higher SiO 2 concentration (72.2–75.9 wt%) than the two-mica granite (69.0–73.0 wt%). In addition, the porphyry is characterized by lower TiO 2 , MgO, CaO, Ba, Sr, and Zr contents as well as Zr/Hf, Sr/Y, Nb/Ta ratios than the two-mica granite. Moreover, strontium and REE contents of monazite in both the two-mica granite and porphyry also imply that crystal fractionation dominated melt evolution. Whole-rock Sr Nd and in situ monazite Nd isotope compositions indicate that the porphyry is slightly more radiogenic than the two-mica granite, implying that the porphyry likely assimilated more ancient country rocks during its evolution. We interpret the two-mica granite and porphyry as comagmatic intrusives linked by fractional crystallization of a cognate magma mush, in which the crystals accumulated to form the two-mica granite, and the complementary high silicic melt segregated to form the porphyry. Plagioclase accumulation is responsible for the generation of the high Sr /Y adakitic geochemical feather within two-mica granite. The scenario of complementary melt extraction and crystal fractionation might also have been an important process in forming the Himalayan leucogranites. Regionally, Neo-Tethyan slab breakoff during the Eocene could have increased mantle heat flow and triggered the generation and extraction of large volumes of silicic melt. • Two-mica granite and subvolcanic rhyolite porphyry have a coeval crystallization age at 44–43 Ma . • Two-mica granite represents cumulate and the porphyry as its complementary highly fractionated melt. • Magma differentiation via melt extraction from crystal mush is an effective mechanism to produce Himalayan leucogranites.

Comparative Study of Discrete PI and PR Controller Implemented in SRG for Wind Energy Application: Theory and Experimentation

The Switched Reluctance Generator (SRG) has been widely studied for Wind Energy Conversion Systems (WECS). However, a major drawback of the SRG system adopting the conventional control is the slow response of the DC link voltage controller. In this paper, a Proportional Resonant (PR) control strategy is proposed to control the output voltage of the SRG system to improve the fast response. The SRG model has a high non-linearity, which makes the design of controllers a difficult task. For this reason, the important practical engineering aspect of this work is the role played by the SRG model linearization in testing the sensitivity of the PR controller performance to specific parameter changes. The characteristics of steady-state behaviors of the SRG-based WECS under different control approaches are simulated and compared. The controller is implemented on a digital signal processor (TMS320F28379D). The experimental results are carried out using a 250 W 8/6 SRG prototype to assess the performance of the proposed control compared with the traditional Proportional Integral (PI) control strategy. The experimental results show that the PR control enhances the steady-state performance of the SR power generation system in WECS. Compared to PI control, the rise and settling times are reduced by 45% and 43%, respectively, without an overshoot.

RGSR: A two-step lossy JPG image super-resolution based on noise reduction

Single Image Super-Resolution (SISR) is a fundamental and important low-level computer vision (CV) task, yet its performance on real-world applications is not always satisfactory. Different from the previous SISR research, we focus on a specific but realistic SR issue: How can we obtain satisfied SR results from compressed JPG (C-JPG) images, which is a ubiquitous image format to greatly release storage space while missing fine details. the JPG SR task is deeply analyzed to discover the connotation. Then, we propose an effective two-step model structure named RGSR, involving two specifically designed components, i.e., JPG recovering and SR generation, instead of the perspective of noise elimination in traditional SR approaches. Besides, we further integrate the cycle loss to build a hybrid objective across scales for better SR generation. Experimental results on both of the standard test data sets and real images show that our approach achieves outstanding results and succeed in applying to practical C-JPG SR tasks.

A New Control Strategy for SR Generation System Based on Modified PT Control

The Switched Reluctance generator (SRG) has been widely used as a constant voltage source due to its advantages of simple structure, low cost and high control flexibility. However, the output voltage ripples cannot be ignored due to its unique operating principle with phase commutation. In this paper, the influence of the control parameters on the output voltage ripples are analyzed, and a fly-wheeling pulse train (FW-PT) control strategy is proposed to suppress the voltage ripple. The output voltage can be regulated by the FW-PT control strategy by using two or more sets of preset control pulse combinations, therefore it has the advantages of simple circuit implementation, no Network compensation and fast response speed. The characteristics of steady-state and dynamic behaviors of the switched reluctance power generation system by using different control strategies are simulated and compared, and a platform of 200W 8/6 SRG is built for experimental verification. Simulation and experimental results confirm that compared with the traditional PID control strategy, the FW-PT control strategy can be used to not only suppress the output voltage ripple, but also achieve faster response and dynamic characteristics.

Study of superoxide- and NO-dependent protective mechanisms of N-acetylcysteine and losartan in ratʼs aorta and liver under streptozoticin-induced type 1 diabetes mellitus

Aim. The aim of the research was to investigate superoxide- (SR) and NO-dependent mechanisms of action of N-acetylcysteine (NAC) and losartan (LOS) in aorta and liver of rats with type 1 diabetes mellitus (DMI).Methods. Diabetic rats were treated with NAC (1.5g/kg), LOS (20mg/kg) or combination (NAC+LOS) for 4 weeks.Results. The rate of SR generation by mitochondria of aorta in untreated diabetic animals was significantly higher than in control, while the level of NO was decreased. Production of SR and NO in the liver of diabetic rats were dramatically increased. The marker of oxidatively damaged DNA, 8-oxoG, was raised in urine of diabetic rats. All of pharmacological schemes showed significant decrease the rate of SR generation by mitochondria of aorta and liver; NO level was lowered in the liver tissue compared to DMI. Only NAC significantly restored NO level in aorta of diabetic rats. Intervention with NAC / LOS or NAC+LOS increased the level of 8-oxoG in compare to DM1.Conclusion. In conclusion, treatment with NAC and LOS or combination is associated with protection of aorta and liver cells in diabetic animals against toxic action of SR, preventing mitochondrial dysfunction and further DNA damage, which point out the cardioprotective effects and overall metabolic improvement

Structured dose reporting

For a long time, radiation dose documentation has been done manually. In the late Nineties, DICOM has introduced MPPS (Modality Performed Procedure Step), which has been the first general solution for digital communication of dose measurements. In parallel, OCR has been used to analyse the “images” keeping dose information, which are part of most CT studies. Both of these efforts have some advantages and also a lot of disadvantages, e.g. MPPS is a message based communication, which could fail and OCR could produce errors. Therefore, some years ago DICOM has started to develop new objects for documentation of dose information as “DICOM Dose Structured Reports”. These objects are full DICOM objects, which can be communicated, stored and displayed like any other DICOM object. Such Dose SRs are available for many different imaging modalities, meanwhile also a Dose SR for nuclear medicine is available (Supplement 159, 2013). Actually, the second generation of Dose SR on Radiotherapy (Suppl. 177) and a “Patient Radiation Dose Reporting” (Suppl. 191) are in discussion in DICOM. The real world application is “prescribed” with the IHE profile on “Radiation Exposure Monitoring”. Based on this profile, different roles for creating, archiving and analysing dose information have been defined and described. This model allows building local, regional or even international dose registers from real life examinations. Such information is optimal for benchmarking or creation of DRLs. Using structured dose information, there are new opportunities for research. Also, in principle there patient-oriented dose-profiles could be created in future. For a long time, radiation dose documentation has been done manually. In the late Nineties, DICOM has introduced MPPS (Modality Performed Procedure Step), which has been the first general solution for digital communication of dose measurements. In parallel, OCR has been used to analyse the “images” keeping dose information, which are part of most CT studies. Both of these efforts have some advantages and also a lot of disadvantages, e.g. MPPS is a message based communication, which could fail and OCR could produce errors. Therefore, some years ago DICOM has started to develop new objects for documentation of dose information as “DICOM Dose Structured Reports”. These objects are full DICOM objects, which can be communicated, stored and displayed like any other DICOM object. Such Dose SRs are available for many different imaging modalities, meanwhile also a Dose SR for nuclear medicine is available (Supplement 159, 2013). Actually, the second generation of Dose SR on Radiotherapy (Suppl. 177) and a “Patient Radiation Dose Reporting” (Suppl. 191) are in discussion in DICOM. The real world application is “prescribed” with the IHE profile on “Radiation Exposure Monitoring”. Based on this profile, different roles for creating, archiving and analysing dose information have been defined and described. This model allows building local, regional or even international dose registers from real life examinations. Such information is optimal for benchmarking or creation of DRLs. Using structured dose information, there are new opportunities for research. Also, in principle there patient-oriented dose-profiles could be created in future.

Reclamation of phosphorus from aqueous solutions as alkaline earth metal phosphate in a fluidized-bed homogeneous crystallization (FBHC) process

This investigation studies the crystallization of alkaline earth metal phosphates (Me-PO4, Me=Mg, Ca, Sr, Ba) to recover phosphorus (1000 ppm-P) in a fluidized-bed reactor without the addition of seeds. Experimental results showed that the effluent pHe critically determined the phosphorus removal rate (PR%) and crystallization ratio (CR%). The PR%s that were achieved by the generation of Mg, Ca, Sr and Ba-phosphates with an inlet molar ratio [Me]in/[P]in of 2 were 77.8%, 99.4%, 97% and 98.9% at the pHe values exceeded 7.5, 6.6, 7.2 and 6.4, respectively. However, the CR% was strictly optimized by a pHe that transformed the crystalline phases of granular pellets (0.5–2mm in diameter) from metal hydrogen phosphate (MeHPO4) to hydroxyapatite (Me5(PO4)3(OH)), and maximum CR%s of 54.5%, 78.8%, 79.0% and 89.0% were obtained by the generation of Mg, Ca, Sr and Ba-phosphates. According to estimates of aquatic chemistries and supersolubility behaviors in the effluent, a successful FBHC process operated under a supersaturation that was close to the metastable zone. Finally, a reasonable mechanism of the removal of phosphorus by converting the aqueous phosphorus into highly pure metal phosphate pellets was inferred.

Sustained Release of Bone Morphogenetic Protein-4 in Adult Rabbit Extraocular Muscle Results in Decreased Force and Muscle Size: Potential for Strabismus Treatment

Purpose. To assess the effect of a sustained-release preparation of bone morphogenetic protein-4 (BMP-4) on EOM force generation and muscle size. Methods. Sustained-release pellets, releasing 500 nanograms/day of BMP-4 for a maximum of 3 months, were implanted beneath the superior rectus muscle (SR) belly in anesthetized adult rabbits. The contralateral side received a placebo pellet as a control. After 1, 3, and 6 months, SRs were removed, and force generation at twitch and tetanic frequencies as well as fatigue resistance were determined in vitro. Myofiber size, myosin heavy chain isoform expression, and satellite cell density were assessed histologically. Results. SR force generation was significantly decreased by BMP-4 compared with the contralateral controls. Force generation was decreased by 25-30% by 1 month, 31-50% by 3 months, and at 6 months, after 3 BMP-4-free months, force was still decreased by 20-31%. No change in fatigue was seen. Significant decreases in muscle size were seen, greatest at 3 months. At all time points Pax7- and MyoD-positive satellite cell densities were significantly decreased. Conclusions. The decreased force generation and muscle size caused by sustained release of BMP-4 suggests that myogenic signaling factors may provide a more biological method of decreasing muscle strength in vivo than exogenously administered toxins. Treating antagonist-agonist pairs of EOM with titratable, naturally occurring myogenic signaling and growth factors may provide safe, efficacious, nonsurgical treatment options for patients with strabismus.

Audio Device And Method For Generating Surround Sound Having First And Second Surround Signal Generation Units

An audio device capable of easily generating two or more sets of surround signals based on 2-channel stereo signals and a method for generating surround sound are provided. The audio device 100 includes: an SL signal generation section 20 and a BL signal generation section 40 as first surround signal generation units for receiving an L signal and an R signal as 2-channel stereo signals, extracting a component of the R signal having high correlation with the L signal, subtracting the component from the L signal, thereby generating a first surround signal; and an SR signal generation section 30 and a BR signal generation section 50 as second surround signal generation units for extracting a component of the L signal having high correlation with the R signal, subtracting the component from the R signal, thereby generating a second surround signal. The level of subtracting a component from the L signal or the R signal for generating the first or second surround signal is differentiated each other between the plural sets.

COMPARISON OF TWO TYPES OF DUAL LAYER GENERATOR IN FIELD ASSISTED MODE UTILIZING 3D-FEM AND EXPERIMENTAL VERIFICATION

This paper presents the comparison results between two new generator conflgurations. These generator units are namely a fleld assisted switched reluctance generator (SRG) and a brushless dc (BLDC) generator. No permanent magnets are used in either unit. The fleld assisted SR generator consists of two magnetically dependent stator and rotor sets (layers), where each stator set includes twelve salient poles with windings wrapped around them, while the rotor comprises of eight salient poles without any winding or permanent magnet. There is a stationary reel, which has the fleld coil wrapped around it and is placed between the two-stator sets. The BLDC generator is also made up of two magnetically dependent stator and rotor sets, but each stator set includes nine salient poles with windings wrapped around them while, the rotor comprises of six salient poles without any windings or permanent magnets. There is also a stationary reel between the two layers to produce the magnetic fleld through the motor assembly. This magnetic fleld travels through a guide to the rotor then the stator and flnally completes its path via the generator housing. The generator phase windings for each layer are connect such that all the stator poles in that set can have either north or south pole conflguration while the stator poles in the other layer have the opposite pole arrangement. This type of connection can be used in motoring mode as well. To evaluate the performance of the generators, two types of analysis, namely, numerical technique and experimental study have been utilized. In the numerical analysis, three dimensional flnite element analysis is employed, whereas in the experimental study, proto-types have been built and tested.

Separation of microamounts of yttrium from strontium by using sodium dicarbollylcobaltate, Slovafol 909 and ethylenediamine - N, N, N', N'-tetraacetic acid in the water - nitrobenzene extraction system

A rapid extraction separation of trace amounts of yttrium from stron tium by a nitrobenzene solution of sodium dicarbollylcobaltate (NaDCC) in the presence of p -nonylphenylnonaethylene glycol (Slovafol 909) and tetrasodium salt of ethylenediamine – N,N,N’,N’ – tetraacetic acid (Na 4L) in the aqueous phase was developed. The separation factor α(Sr/Y) was substantially higher than 10 5 . This water -nitrobenzene extraction system can be applied for the efficient separation of carrier -free 90 Y from 90 Y/ 90 Sr generator.

Sulfur and strontium isotope geochemistry of tributary rivers of Lake Biwa: implications for human impact on the decadal change of lake water quality

To study the deterioration of the water quality in Lake Biwa, Japan, over the last 40 years, we measured the concentrations and isotopic ratios of sulfur and strontium of water in 41 inflowing rivers and one discharging river. The concentrations of SO 4 and Sr of inflowing rivers at downstream sites were generally high in the southern urban area and in the eastern area, where a large agricultural plain is situated, but low in the northern and western areas, whose watersheds are mountainous and with low population density. SO 4 and Sr concentrations are also lower at upstream sites, which are closer to mountainous areas. Thus, the inflowing river receives large amounts of SO 4 and Sr as it flows across the plain, where human activity levels are high. The δ 34S or 87Sr/ 86Sr values of most eastern rivers at downstream sites are lower than those of water in Lake Biwa, and values become more uniform as the proportion of the plain area in the watershed increases. River water in other areas has higher values of δ 34S or 87Sr/ 86Sr than the lake water. This result indicates that the decadal decrease of δ 34S and 87Sr/ 86Sr in the lake water has been caused mainly by the increased flux of SO 4 and Sr from rivers in the eastern plain. We assume that in the plain, sulfur, nitrogen, and organic compounds induced by human activities generate sulfuric, nitric, and organic acids in the water, which accelerate the extraction of Sr from bedrocks, leading to the generation of Sr in the river water in the area.

Collisional dynamics of low energy states of atomic strontium following the generation of Sr(5s5p 1P 1) in the presence of Ne, Kr and Xe

The population dynamics of the lower energy excited states of atomic strontium, namely, 1D 2, 3D J , 3P 2, 3P 1 and 3P 0, have been investigated by time-resolved laser-induced fluorescence following pulsed laser excitation to the Sr[5s5p( 1P 1)] state at 760 K in presence of the noble gases Ne, Kr and Xe. In addition, the 1P 1 and 3P 1 states were monitored by spontaneous emission under intentionally quantified conditions of radiation trapping for Sr( 1P 1). The kinetic model employed yields a set of kinetic rate constants, radiation data, collisional propensity rules and the correlation of collisional cross-sections for all the noble gases with potential well depth.

St. Thomas Hospital Cardioplegia #2 fails to suppress slow reaction pacemaker cell electrical activity 1

Background Inadequate right atrial myocardial preservation during cardioplegic arrest may promote postoperative supraventricular arrhythmias (SVA). We determined (1) if oxygenated St. Thomas Hospital Cardioplegia #2 (STH2) alone causes slow reaction pacemaker cell (SR) quiescence; and (2) if hypothermia, higher [K +], lower [Ca 2+], and verapamil in STH2 suppresses SR electrical activity. Materials and methods A glass microelectrode recorded SA node SR membrane action potentials (AP) in rabbits ( n = 23, 1.93 ± 0.45 kg) randomized to normothermic STH2 (33°C, n = 6), hypothermia (20°C, n = 4), hypothermic STH2 (22°C, n = 3), lower calcium STH2 ( n = 3), higher potassium STH2 ( n = 4), and STH2 plus Verapamil ( n = 3). Results Normothermic STH2 depressed SR action potential amplitude and action potential duration (APD), but did not completely suppress action potential generation. Hypothermia alone prolonged APD and sinus cycle length and suppressed SR AP. STH2 with hypothermia (to 20°C) completely suppressed propagating AP and STH2 plus 0.04 Ca 2+ mEq/L inhibited SR AP generation. STH2 plus 30 mEq K + and STH2 plus 2.5 mmol/L verapamil failed to generate SR AP. Conclusion STH2 cannot prevent SA node SR myocardial cells from low-amplitude AP autogeneration above 21°C. STH2 with 30 mEq/L K +, STH2 with 0.02mEq/L Ca 2+, and STH2 plus 2.5 mmol/L verapamil can arrest AP generation in SR and potentially prevent postoperative SVA.

Collisional dynamics of low energy states of atomic strontium following the generation of Sr(5s5p1P1) in the presence of He and Ar

An experimental study is reported on the dynamics of the set of energy states below the 5s5p(1P1) state of atomic strontium, namely 1D2, 3DJ, 3P2, 3P1 and 3P0, in the presence of the rare gases He and Ar and at temperatures from 673 to 760 K. These were generated following the nanosecond pulsed laser excitation of ground state Sr vapour at λ = 460.07 nm {Sr[5s5p(1P1)] ← Sr[5s2(1S0)]}, intentionally employing radiation trapping to lengthen the effective lifetime of Sr(1P1) and so facilitate population of these lower lying states by emission and collision. The populations of the lower states were then interrogated by laser-induced fluorescence (LIF) at selected delays and, where possible, also by spontaneous emission methods. The evolution of the populations with time have been modelled with a set of coupled linear differential equations yielding a consistent set of collisional rate data and emission lifetimes. The individual populations of the closely spaced spin–orbit states within Sr(3DJ) cannot be separated on the time scale of the pulsed lasers and are treated as a single state. By contrast, for most rare gases, intramultiplet mixing within Sr[5s5p(3P0,1,2)] is slow and the J states are treated separately. The collisions of Sr(5 1P1) with Ar and He have been shown to yield mainly Sr(5 3DJ) with negligible yields of both Sr(1D2) and Sr(5 3PJ). The model uses relative values of Einstein coefficients from the averaged Sr(5 3DJ) state to any of the three Sr(5 3P0,1,2) states, calculated assuming an LS coupling approximation for Sr and normalised to the overall experimental Einstein coefficient. The six-state kinetic model proposed, constructed incorporating earlier measurements specifically on Sr(5 3P0,1,2), is shown to fit well the observed population profiles and also shows collisional propensity behaviour.

Fault Analysis and Excitation Requirements for Switched Reluctance Generators

Switched reluctance machines (SRMs) are a prime candidate for aerospace starter/generators and various automotive applications. The choice of SRMs for the starter/generator application is driven largely by the perceived reliability and fault tolerance of the machine and its electronics. An analysis of the switched reluctance generator's (SRG) faults and excitation requirements is essential to utilize the full fault tolerance capability of the machine in this application. Thus, research has been undertaken to identify, analyze and simulate the various fault modes of the SRG. This research included an investigation of the generator's excitation requirements with and without faults. The investigation makes it possible to determine the size of the excitation source required during the initial build up of the generator's output voltage and under fault conditions. The SR machine, controller, EMI filter, excitation source, and load were all modeled and integrated into a Matlab-Simulink model in order to analyze the SR generator system.

Separation of microamounts of yttrium from strontium in the two‐phase water/nitrobenzene system

A rapid and very effective separation of carrier‐free 90 Y in the aqueous phase of the water/nitrobenzene system from an 90 Y/90 Sr generator is proposed. After a two‐stage extraction separation, the radionuclide impurity of 90 Sr in the final aqueous phase containing carrier‐free 90 Y is approximately 10 ‐16%, while the chemical yield of 90 Y in this phase is practically 100%.

Collisionally induced intramultiplet mixing of Sr(5 3P J) metastable states by He, Ar and Sr ground state atoms

Intramultiplet collisionally induced mixing within the Sr[5s5p( 3P 0,1,2)] manifold is investigated by time-resolved laser-induced fluorescence (LIF) following the pulsed dye-laser generation of Sr( 3P 1) of the electronic ground state {Sr[5s5p( 3P 0,1,2)]←Sr[5s 2( 1S 0)], λ=689.26 nm} at elevated temperatures. The population profiles of the three spin–orbit states were individually monitored by LIF as well as that of Sr( 3P 1) by spontaneous emission at the resonance wavelength. A kinetic model is employed that enables the process of spontaneous emission from Sr( 3P 1) to be isolated initially and characterised by experiment. Particular emphasis is placed on the modelling procedure itself in which the separate kinetic component due to spontaneous emission and the positions of the maxima in the 3P 0 and 3P 2 population profiles constitute severe constraints on the model. The collisional components within the model are reduced to three rate constants where pairs of J states are connected in this context by detailed balance. Thus k 10 and k 12, and, by detailed balance, k 01 and k 21 are quantified at various temperatures and pressures to yield the absolute value of these collision properties for Sr( 3P J ) with He and Ar. Rate data for collisionally induced intramultiplet mixing in Sr( 3P J ) by Sr( 1S 0) itself is also reported found to proceed at close to unit collisional efficiencies in all cases. Thus, at elevated temperatures, variations in atomic profiles are dominated by the differing vapour pressures of atomic strontium. Estimates of the activation energies associated with k 10 and k 12 for the noble gases observed against this large competing background are found to be of the order of the spin–orbit splittings. The model overall is found to be insensitive to k 02 and k 20 whose magnitudes are small by comparison with those for the collisional rate data connecting adjacent J states. Whilst collisional processes for He are some two orders of magnitude more efficient than those for Ar, all of these are seen to be ‘adiabatic’, in contrast with the gas kinetic rate constants of ground Sr, considered to be ‘sudden’ in character. The results are compared with analogous data derived by atomic resonance absorption spectroscopy following pulsed generation of Sr( 3P 1) and are considered in the context of theoretical calculations employing quantum close coupling calculations.