Interruption Method Research Articles

Is “Whole Child” Education Obsolete? Public School Principals’ Educational Goal Priorities in the Era of Accountability

Objectives: Working under the constraints of external accountability policy, public school principals are faced with challenges in prioritizing educational goals. Using the Schools and Staffing Survey (SASS) data sets, this study examined the nature and sources of changes in principals’ educational goal priorities in the era of accountability, including the No Child Left Behind Act (NCLB). Method: Difference-in-differences method was used to compare the national average trends of educational goal priorities between public and private schools during 1991–2012 period. Comparative interrupted time series method was also used to explore the impact of NCLB accountability policy on those trends across 50 states. At the school level, logistic regression was applied to examine the effect of NCLB Adequate Yearly Progress status on principals’ educational priorities. Results: While academic goals gained traction over the 1991–2012 period, there were setbacks for other goals of education, particularly personal growth and vocational skills. Notably, public schools’ priority changes were more drastic than private schools’ changes. The divergent trends largely persisted after NCLB across the states. On the other hand, public school principals who previously failed to meet NCLB targets gave more emphasis on basic skills and less emphasis on academic excellence and personal growth. Conclusion: Public school principal’s priorities on academic goals have been shaped by test-driven accountability measures, while other equally important goals have been possibly deprioritized. It gives implications for the implementation of the Every Student Succeeds Act, in which educational leaders can redesign accountability systems and incorporate nonacademic measures for whole child education.

Salt-concentrated acetate electrolytes for a high voltage aqueous Zn/MnO2 battery

Aqueous rechargeable Zn/MnO2 batteries are attractive due to their low-cost, high safety and use of non-toxic materials. In term of electrolyte materials, it is anticipated that an aqueous electrolyte with a wider electrochemical window will improve the stability and energy density. In this work, we investigated salt-concentrated electrolytes based on relatively inexpensive acetate salts. An electrochemical window of 3.4 ​V was achieved in salt-concentrated 1 ​m Zn(OAc)2+31 ​m KOAc electrolyte. Its total ionic conductivity is 2.96 ​× ​10-2 ​S ​cm-1 while the ionic conductivity of Zn2+ ions is 7.80 ​× ​10-3 ​S ​cm-1, estimated by a current interrupt method. This electrolyte is regarded as a mild alkaline environment with a pH value of 9.76, causing the different storage mechanism for anode with Zn2+ ions and, cathode with OH- ions as the charge carriers respectively. A Zn/MnO2 battery was assembled using 1 ​m Zn(OAc)2+31 ​m KOAc electrolyte, self-supported α-MnO2-TiN/TiO2 cathode and Zn foil anode. The Zn/MnO2 battery can be charged to 2.0 ​V versus Zn/Zn2+ and delivers discharge capacity and energy density of 304.6 ​mAh·g-1 (calculated on the mass of MnO2) or 0.32 mAh·cm-2 (calculated on the area of electrode) and, 368.5 ​Wh·kg-1 (calculated on the mass of MnO2) or 232.7 Wh·kg-1 (calculated on the total active mass of electrodes and electrolyte) in the first cycle under a current density of 100 mA·g-1 (~ C/3, based on the mass of MnO2) or 0.1 mA·cm-2 (based on the area of electrode). During cycling, the coulombic efficiency can be maintained around 99% and reached 99.9% during the 14-340th cycles. After the cycling tests, almost no dendrites were observed on the Zn foil anode attributing to the super-high salt concentration in that acetate-based electrolyte, which will benefit the stability of aqueous Zn/MnO2 batteries.

Abstract P250: The Impact of Recreational Cannabis Legalization on All-cause Hospitalizations and Acute Cardiovascular Event Hospitalizations in Colorado

Background: Cannabis may have adverse consequences for cardiovascular health. Colorado decriminalized cannabis on November 2012 and retail sales of cannabis began in January 2014. We examined whether the overall rate of hospitalizations and hospitalizations for acute cardiovascular events (ACE) increased in Colorado after legalization. Hypothesis: We hypothesized that the rates of all-cause hospitalizations and ACE would increase post legalization of recreational cannabis. Methods: The State Inpatient Database (SID) for Colorado, available through Healthcare Cost and Utilization Project was analyzed using interrupted time-series methods to assess whether increases in sales of marijuana affected the rates of overall hospitalization and hospitalization for ACE, post legalization of cannabis. The time analyzed included January 2008 through September 2015. We ended the data of analysis on October 1 2015, because ICD-10 codes were implemented in October 2015. The primary outcome, rate of hospitalizations, was measured by total unique inpatient admissions within the SID for each monthly time period. The secondary outcome, ACE, was identified using ICD-9 diagnostic codes for myocardial infarction (410), stroke (430, 431, 433, 434, 436), and ICD-9 procedure codes for coronary artery bypass surgery (36.1x), and percutaneous coronary intervention (36.0x, 0.66). In the interrupted time series regression models we accounted for seasonality and consumption of cigarettes and alcohol using a proxy of sales tax collected each month for cigarettes and alcohol. In the ACE models, we controlled for seasonality, sales of cigarettes and average monthly air temperature. We also examined the effect of legalization on the same outcomes in men and women and different age subgroups. Results: While overall rates of hospitalizations decreased somewhat over the study period, there was no statistically significant difference in hospitalizations rates, neither in the regression intercept (for immediate change) (p=0.94) or slope (p=0.97), after the legalization of recreational cannabis. Similarly, ACE rates decreased over the time frame, but there were no significant changes in rate intercept (p=0.80) or slope (p=0.71) post legalization. The subgroup analyses by age category and gender for hospitalizations and ACE also showed no significant differences in rates pre and post legalization. Conclusions: We found no evidence that overall hospitalizations and hospitalizations for ACE increased due to legalizing recreational cannabis in Colorado. A limitation of our study was that Colorado had already implemented a medical marijuana program in 2000. Recreational legalization may not have led to a significant increase in users. Future studies should examine the link between legalization and cardiovascular events in other states with a different trajectory of legalization.

74 Effects of Community Falls Prevention Service Closure on Ischaemic Heart Disease Attendances in Secondary Care: An Interrupted Time Series Approach

Abstract Background In 2009 we implemented a novel multidisciplinary, multifactorial falls, syncope and dizziness service model utilising proactive, primary care-based screening (≥60 years). Participants underwent comprehensive geriatric assessment, while 25% of the 4032 service participants had exercise training. All had additional lifestyle advice on exercise, alcohol intake, weight loss and smoking cessation. The preliminary outcomes of this approach have been previously reported, with occult atrial fibrillation, murmurs, ECG-evident ischaemic heart disease (IHD) etc reported to GPs for further action.1 Funding was withdrawn and the service closed on 31/01/2014. We examined IHD secondary care attendances with and without service provision. Methods Patients: North Tyneside residents ≥60 years at time of closure of the service in January 2014, who were presented acutely to secondary care with IHD using an interrupted time series method. ICD-10 coded IHD numbers were determined (Hospital Episode Statistics from 01/02/2012[date of a change in coding compared to service commencement in 2009] until 31/05/2017) including 25-months with, and 40-months without, service provision. Results The Table summarises the change in IHD +/- service provision; there was a significant reduction in IHD non-elective admissions during both time series’, but the reduction was significantly lower without service provision. In addition, immediately following the service closure there was an initial increase in IHD complications of 18.4% (p=0.059) followed by an increase in the time trend of 2.7% (p=0.029), resulting in a 0.6% post-service monthly reduction in IHD complications. Conclusions Disinvestment in this service resulted in a slowdown in the underlying reduction of IHD diagnoses in secondary care. However, further research is needed to control for patient-level characteristics, the economic impact and to look at the effect of the service on other cardiovascular diseases. Reference 1. Parry SW. JAGS 2016; 64 (11):2368–2373.

Absorbable versus conventional methods for wound closures in surgeries for benign breast diseases: a randomized case control study

Background: Surgeons and patients prefer absorbable sutures for surgical wound closure in breast surgeries which are usually continuous subcuticular sutures so that patients can skip a hospital visit for suture removal. But in case of breast biopsies authors usually put circumareolar incisions. Here authors find it difficult to put continuous subcuticular sutures. In this contest authors thought of interrupted subcuticular sutures where authors can tackle the above-mentioned limitations; while actually reducing the financial burden of the patients.Methods: In this randomized case controlled study authors included elective general surgical procedures for benign breast diseases that was being carried out in the department of General Surgery Govt. Medical College, Kottayam for a period of 6 months starting from January 2017. Total number of cases taken are 20; 10 each in each group.Results: The mean rank for interrupted method was 14.20 and conventional method was 6.80. Mann-Whitney U statistic was 13.000 and p value was 0.03. Since p value was less than 0.05, authors had clear evidence to reject the null hypothesis. Therefore, authors concluded that both the methods were dissimilar and based on mean rank interrupted method seemed to be better method.Conclusions: Authors recommended interrupted absorbable subcuticular suturing technique in general surgical procedures for benign breast diseases, especially where authors used circumareolar incisions, which saved time of the surgeon and the patient. This can lead to considerable cost savings for the government without compromising clinical effectiveness or safety.

Short-circuit fault current-limiting characteristics of a resistive-type superconducting fault current limiter in DC grids

Resistive-type superconducting fault current limiters (R-SFCLs) can limit short-circuit fault current and help DC circuit breakers (DCCBs) to isolate short-circuit faults in medium voltage and high voltage DC (HVDC) systems. SFCLs are always used with circuit breakers to break short-circuit current in power systems. The interruption characteristics of the DCCBs influence the current-limiting characteristics of the SFCLs. However, there has been a lack of investigation into the current-limiting and interruption characteristics when R-SFCLs are combined with mechanical-type DCCBs (M-DCCBs) based on the self-excited oscillation interruption principle in medium voltage and HVDC systems. The objective of this paper is to obtain the short-circuit fault current-limiting characteristics of a designed R-SFCL combined with an M-DCCB in DC grids. This paper describes the design of a 10 kV DC R-SFCL which was tested in combination with an M-DCCB in a DC circuit in order to obtain the quenched resistance and the required current interruption characteristics. Besides, a modular multilevel converter-based multi-terminal direct current (MMC-MTDC) grid was used to investigate the current-limiting and interrupting characteristics of the R-SFCL and the M-DCCB in a realistic HVDC grid. The experimental results show that in the 10 kV DC circuit the R-SFCL combined with the M-DCCB limited a 10 kA DC to the peak value of 1416 A and then interrupted this limited current successfully. And unlike other methods of DC interruption, this did not create overvoltage after interruption. The highest voltage on the R-SFCL is the system voltage during interruption. This means that the R-SFCL can effectively delay the voltage drop in MMC-MTDC grids, and provide enough time for the M-DCCB to interrupt the limited current. Thus, a combination of R-SFCLs and M-DCCBs might be an effective and reliable method to interrupt short-circuit fault currents in medium voltage and HVDC grids.

Simultaneous Monitoring of Crystalline Active Materials and Resistance Evolution in Lithium–Sulfur Batteries

Operando X-ray diffraction (XRD) is a valuable tool for studying secondary battery materials as it allows for the direct correlation of electrochemical behavior with structural changes of crystalline active materials. This is especially true for the lithium-sulfur chemistry, in which energy storage capability depends on the complex growth and dissolution kinetics of lithium sulfide (Li2S) and sulfur (S8) during discharge and charge, respectively. In this work, we present a novel development of this method through combining operando XRD with simultaneous and continuous resistance measurement using an Intermittent Current Interruption (ICI) method. We show that a coefficient of diffusion resistance, which reflects the transport properties in the sulfur/carbon composite electrode, can be determined from analysis of each current interruption. Its relationship to the established Warburg impedance model is validated theoretically and experimentally. We also demonstrate for an optimized electrode formulation and cell construction that the diffusion resistance increases sharply at the discharge end point, which is consistent with the blocking of pores in the carbon host matrix. The combination of XRD with ICI allows for a direct correlation of structural changes with not only electrochemical properties but also energy loss processes at a non-equilibrium state, and therefore is a valuable technique for the study of a wide range of energy storage chemistries.

Surface morphology and optical properties of InGaN quantum dots with varying growth interruption time

The effect of different growth interruption time on the surface morphology and optical properties of InGaN quantum dots (QDs) grown on 2-inch silicon substrates is investigated. The surface becomes rougher and the photoluminescence intensity has been enhanced significantly when employing the growth interruption method. Temperature-dependent photoluminescence and excitation power-dependent photoluminescence both present unchanged peak energy and line-width of QDs. The sharp increase of PL intensity in medium temperature regime is attributed to the fingerprint of the existence of InGaN QDs. The shape of the QDs are further confirmed by the transmission electron microscopy with a size of 3 nm by 4 nm. Among the samples, a growth interruption time of 30 s gives the best optical performance.

Estimating vocal fold stiffness: Using the relationship between subglottic pressure and fundamental frequency of phonation as an analog.

The stiffness of the vocal folds is an important factor in voice production, yet clinically applicable measurements are still lacking. It has been demonstrated in an in vivo canine model that fundamental frequency (F0 ) increased linearly as subglottic pressure (Ps ) increased, but with a lesser slope for higher levels of vocal fold tension. In this study, the relationship between F0 and Ps was investigated using the airflow interruption method in awake patients non-invasively. Healthy volunteers enrolled for evaluation. Single-centre. Thirty-three healthy volunteers aged 20 and older were recruited, with one excluded for a recent asthma attack. The relationships between F0 and Ps , described as the slope (Hz/kPa), were investigated when the participants sustained voicing the vowel/o/at 3 incremental frequencies 4 semitones apart in the modal register (F1, F2 and F3). Thirty-two healthy volunteers (20 females, 12 males) aged 20-47years were enrolled for final analyses. There was a statistically significant difference in the slopes of the linear regression lines of F0 -Ps , depending on the frequency with which the vowel/o/ was produced (P<.001). The slope differed significantly between F2 and F1 (P<.001; P=.015), F3 and F1 (P<.001; P=.002) and F3 and F2 (P<.001; P=.005) for both women and men, respectively. It was demonstrated that the higher the vocal fold tension, the smaller the slope between F0 and Ps . Using the relationship between F0 and Ps as an analog of vocal fold stiffness is potentially practical for clinical application.

Overcoming Hepatic Artery Thrombosis After Living Donor Liver Transplantations: An Experience from Asan Medical Center.

BackgroundHepatic artery (HA) reconstruction in living donor liver transplantation (LDLT) is more technically demanding than deceased donor LT (DDLT) because of the small diameter and short HA stump of the partial liver graft. Hence, hepatic artery thrombosis (HAT) can occur infrequently even though the HA is reconstructed microscopically. HAT is closely related to graft failure and mortality. Therefore, HAT should be detected early and HA flow reconstituted using several arterial inflows. We successfully performed redo HA reconstruction in LDLT and report our management process and outcomes.Material/MethodsThe right gastroepiploic artery (RGEA) was used in 15 patients, previous native HA in 3, and interposition graft from the aorta in 1. All HA reconstructions were performed under a microscope using the end-to-end interrupted suture method. We reviewed technical feasibility, cause of hepatic artery revision (HAR), patency of redo HA flow, graft salvage rate, time of revision, biliary complications, and mortality.ResultsTen of 21 cases were salvage LT. Biliary complications developed in 6 cases. The mean interval of HAR with the RGEA was 1.5±1.2 postoperative days. All patients were alive without lethal complications of HAT during the mean follow-up period of 23.3 months. In the other 6 cases of HAR without using the RGEA, we performed redo HA reconstruction after thrombectomy with the native right HA (n=2), right gastric artery, left HA, gastroduodenal artery, and jump graft from the aorta (n=1, respectively). Among them, 3 died from biliary sepsis, graft dysfunction from large-sized ischemic injury, and pneumonia.ConclusionsHAR with the RGEA is feasible for HAT management in LDLT patients without adequate hepatic arteries. When all inflows mentioned are unavailable, jump graft from the aorta using a cadaveric fresh iliac artery may be feasible.

Decreasing Colectomy Rate for Ulcerative Colitis in the United States Between 2007 and 2016: A Time Trend Analysis.

Improved treatment approaches for ulcerative colitis (UC), including novel medications, might reduce the need for colectomy. We performed a retrospective cohort study of adult patients (age 18-64) with UC in the United States to examine time trends for colectomy and biologic use from 2007 to 2016. We estimated quarterly rates for colectomy and biologic use using the IQVIA Legacy PharMetrics Adjudicated Claims Database. We used interrupted time series methods with segmented regression to assess time trends with 95% confidence intervals (CIs) for biologic use and colectomy before and after the emergence of newly available biologic therapies in 2014. Among 93,930 patients with UC, 2275 (2.4%) underwent colectomy from 2007 to 2016. Biologic use rates increased significantly from 2007 to 2016, from 131 per 1000 person-years in 2007 (95% CI, 121 to 140) to 589 per 1000 person-years in 2016 (95% CI, 575 to 604; P < 0.001). Colectomy rates decreased significantly between 2007 and 2016, from 7.8 per 1000 person-years (95% CI, 7.4 to 8.2) to 4.2 per 1000 person-years in 2016 (95% CI, 3.2 to 5.1; P < 0.001). An interruption in 2014 was associated with a positive trend deflection for biologic use (+72 treatments per 1000 person-years per year (95% CI, 61 to 83) and a negative trend deflection for colectomy (-0.76 per 1000 person-years per year; 95% CI, -1.47 to -0.05). Among commercially insured patients in the United States from 2007 to 2016, biologic use rates increased, colectomy rates decreased, and both trends were impacted by the interruption in 2014. These findings suggest that new biologic therapies may have contributed to decreased colectomy rates.

Developmental Changes in the Philippine Health System: Accomplishments, Successes and Challenges.

The Philippine health system has undergone various changes which addressed the needs of the time. These changes were reflected in the benchmarks and indicators of performance of the whole health system. To understand how these changes affected the health system (HS), this study determined the changes in the Philippine health system in relation to different health domains (health determinants, financing, and management/development). Two HS periods were identified, namely, health system period 1 (HS 1) from 1997–2007 and health system period 2 (HS 2) from 2008–2017. Each HS period was assessed based on three domains. The first two domains were quantitatively assessed based on an interrupted time-series method, while the third one underwent a comparative analysis using two Health Systems in Transition reports (2011 and 2018). This study was able to assess the developmental changes in the Philippine health system. Specifically, the (health determinant) maternal mortality rate (MMR) significantly decreased by three maternal deaths per 100,000 live births, the (health financing) tobacco excise tax increased by 13,855 (in Million PhP) in HS 2, and there was (health management/development) an improvement in access to health facilities. However, there was an indication of retrogressive progress with some challenges in HS 1 which remained unaddressed in HS 2. While it seems promising that the health system has progressed with improvements apparent in both health outcomes (e.g., MMR) and health financing (e.g., tobacco excise tax), such improvements were overshadowed by the inefficiencies, which were not addressed by the current health system (HS 2), thus making it more retrogressive than progressive.

Variable impact of an antimicrobial stewardship programme in three intensive care units: time-series analysis of 2012–2017 surveillance data

Preprescription authorization (PPA) and postprescription review with feedback (PPRF) were successively implemented in 2012 and 2016 in our 1500-bed hospital. The impact of PPA and PPRF on carbapenems use and resistance levels of Pseudomonas aeruginosa was assessed in three intensive care units (ICUs). Carbapenems use (in DDDs/1000 occupied bed-days) and resistance of P.aeruginosa (percentage of non-susceptible (I+R) isolates to imipenem and/or meropenem) were analysed using a controlled interrupted time-series method. Two periods were compared: 2012-2015 (PPA) and 2016-2017 (PPA+PPRF). Models were adjusted on the annual incidence of extended-spectrum β-lactamase-producing enterobacteriacae. Carbapenem use was stable over the PPA period in all ICUs, with a significant change of slope over the PPA+PPRF period only in ICU1 (β2= -12.8, 95% confidence interval (CI)= -19.5 to -6.1). There was a switch from imipenem to meropenem during the PPA period in all three units. Resistances of P.aeruginosa were stable over the study period in ICU1 and ICU2, and significantly decreased over the PPA+PPRF period in ICU3 (β2= -0.18, CI= -0.3 to -0.03). In real-life conditions and with the same antimicrobial stewardship programme (AMSP) led by a single team, the impact of PPRF was heterogeneous between ICUs. Factors driving the impact of AMSPs should be further assessed in comparable settings through real-life data, to target where they could prove cost-effective.

Esclarecimento da população de Dourados MS sobre o uso indiscriminado de anticoncepcionais como agente causador de hiperplasia mamária

A densidade populacional de cães e gatos aumenta exponencialmente a cada ano e a adoção de métodos de interrupção do ciclo reprodutivo têm sido descritos para o controle desta, sendo a forma amplamente utilizada a farmacológica consistindo na aplicação de anticoncepcionais veterinários de efetiva ação, porém com efeitos adversos. Sendo assim o objetivo deste trabalho foi avaliar o grau de esclarecimento da população de Dourados-MS sobre a posse responsável de cães e gatos no que diz respeito às formas de controle reprodutivo bem como o conhecimento das possíveis patologias decorrentes da utilização de fármacos anticoncepcionais. Para tanto, foi aplicado questionário contendo questões relacionadas à temática, cujo preenchimento ocorreu de maneira manual ou eletrônica por 200 entrevistados escolhidos aleatoriamente. Verificou-se que a população que compôs a pesquisa consistia de indivíduos com instrução acadêmica (74% possuíam nível superior) e elevado poder aquisitivo (33% com renda familiar superior a 3 salários mínimos) que alegaram conhecer os riscos da administração de fármacos anticoncepcionais (88,5%) porém que ainda fazem uso deste método (14%) como forma de controle populacional possibilitando a ocorrência de alterações reprodutivas em seus animais (19,9%). Sendo assim é necessário maior esclarecimento da população sobre o bem-estar animal já que se verificou que o fator financeiro não consistiu em um parâmetro que determinasse a não adoção de métodos cirúrgicos de esterilização.

Development of a novel 1-trifluoroacetyl piperidine-based electrolyte for aluminum ion battery

The first example of chloroaluminate ionic liquids (ILs) analogues based on amides of fluorinated carboxylic acids, namely 1-trifluoroacetyl piperidine (TFAP), has been described. The possibility of applying of this electrolytes has been experimentally evaluated in the series TFAP/AlCl3; TFAP/LiCl/AlCl3; TFAP/[EMIm]Cl/AlCl3; [EMIm]Cl/AlCl3 for use in an aluminum ion battery. The specific conductivities measured by the method of current interruption and impedance spectroscopy at 30 °C were 0.49, 0.28, 1.37, 20.23 mS cm−1, respectively. The exchange current densities at the two-phase interface aluminium/electrolyte investigated using the impedance spectroscopy method were 0.18, 0.03, 0.42, 1100 μA cm−2, respectively. TFAP-based electrolytes did not crystallize when cooled down to −60 °C, according to DSC data. The presence of the molecular [AlCl3(TFAP)], and the ionic AlCl4−, [AlCl2(TFAP)4]+, and [Al(TFAP)6]3+species is proposed based on the 27Al NMR spectra of the studied new ILs analogues.

Operando X-Ray Diffraction of Lithium-Sulfur Batteries with Concurrent Resistance Measurement

Lithium-sulfur (Li-S) batteries have been viewed as one of the promising electric energy storage technologies due to the high theoretical energy density and the abundance of sulfur [1]. However, the utilization of sulfur is typically only 60-70% given the commonly reported reversible capacity of ~1000 mAh/g compared with the theoretical capacity of 1672 mAh/g [2]. The complicated reaction mechanism at the positive electrode is one of the causes for this discrepancy [3]. Though the charged (elemental sulfur, S) and discharged (lithium sulfide, Li2S) states are solid, the reaction intermediates (Li2Sx, x=4-8) are soluble in ether-based electrolytes, e.g. 1,3-dioxolane (DOL) [3]. Therefore, the active material goes through repeated dissolution and precipitation during cell operation. Furthermore, both S and Li2S are insulating, so a conductive porous carbon matrix is required as a host structure [1]. The precipitation of the insulating S and Li2S particles can decrease the electronically-conductive surface area or even block the pores in the carbon matrix, which leads to incomplete reaction and thus low utilization of active material [3]. In this work, the correlation between the evolution of the solid species and the electrochemical response of the porous electrode is investigated by operando X-ray diffraction (XRD) coupled with the Intermittent Current Interruption (ICI) method [4]. The ICI method is a facile way to follow the real-time internal resistance of a battery cycling at a constant current. Periodic transient current pauses are applied to obtain the potential response of the system [4]. From the potential-time relationship, both time-independent and time-dependent parts of the resistance can be derived. The time-independent resistance has been shown to correspond to the sum of the resistive elements in an equivalent circuit model of the electrochemical impedance spectroscopic (EIS) response [4]. In terms of the electrochemical process, the time-independent resistance includes the electronic, ionic and charge transfer resistances. In our recent work [5], the time-dependent part of the resistance from ICI measurements is analyzed by comparison with the existing porous electrode model. This enables us to characterize the mass transport in the positive electrode during the evolution of the solid species as captured by operando XRD. Along with the resistance profile, this work will present the results from in-house operando XRD of a Li-S cell with our cell design, which is dedicated to preserve the reproducible electrochemical properties while offering a satisfactory signal-to-noise ratio in the XRD data. With the information of the mass transport in porous electrode and evolution of crystalline species, the concurrent analyses of both techniques will illustrate the dynamic interaction between the solid sulfur species and the carbon matrix at the positive electrode of Li-S batteries. Figure: Operando XRD results with the diffraction pattern as the heatmap at the top, followed by the cell voltage (E), time-independent resistance (R) and time-dependent resistance (k). The legend for the colors used in the heatmap and following curves are labeled at the top and bottom of the graph.

인버터의 직류 고장전류 차단 방법

인버터의 직류 고장전류 차단 방법

Evaluation of overpotentials on graphite and liquid Bi–Mg electrodes by current interruption

Our group proposes a new titanium smelting process via Bi–Ti alloy. This process is comprised of reduction of TiCl4 by Bi–Mg liquid alloy, separation of Ti from Bi by distillation, and Mg electrolysis. In this study, the Mg electrolysis with Bi–Mg liquid alloy cathode was investigated. We firstly measured the IR-corrected polarization curves on graphite and Bi–Mg liquid alloys by the current interruption method. The results indicated that the Bi–Mg alloy cathode can reduce the electricity consumption of the Mg electrolysis. In addition, from the relaxation curves on graphite and Bi–Mg alloys, the concentration overpotential on the Bi–Mg alloy is mainly due to mass transfer of Mg from the electrode/molten salt interface to the liquid alloy bulk. At current densities higher than 300 mA cm−2, Mg-rich solid phases such as Bi2Mg3 and/or pure solid Mg are assumed to be deposited on the Bi–Mg liquid alloy cathode. Finally, we estimated the electricity consumption of the Mg electrolysis in the new smelting process based on the measured overpotentials, assuming that Bi–Mg liquid alloy cathode is stirred sufficiently and a low current density, 275 mA cm−2, is applied. Under these conditions, the total electricity consumption of the Mg electrolysis in the new process will be lower than that in the Kroll process when the anode–cathode distance is smaller than 8 cm. IR-corrected polarization curves of (a) Mg2+ reduction on graphite and Bi–Mg liquid alloys and (b) Cl2 evolution on graphite in MgCl2–NaCl–KCl at 550 °C were measured by the current interruption method, and electricity consumption of Mg electrolysis in the new Ti smelting process was estimated from these results.

An Arc Squeeze Method for DC Interruption—Experiments and Analysis

Conventional air dc circuit breakers face the problems of complex arc motion control and arc back-commutation. In order to simplify the arc motion control, solve the arc back-commutation, and shorten the breaking time, this paper proposes an arc squeeze method, which stretches the arc in the insulating slit to make the arc voltage rise. The arc voltage acts as counter voltage to the system voltage and causes the current to cross zero, and then, current interruption is completed. For the experimental study, a test device was designed and made. The effects of different structural parameters (penetration depth of insulating plate, slit cross section circumference, and area) and external parameters (operating speed of insulating plate and peak circuit current) on the arc voltage increase during the breaking process were studied and analyzed. The interruption time of fault current with maximum value within 12–22 kA is quite short (about 5 ms).

Impact of the ERA and GES health programs on mortality from community-acquired pneumonia in persons aged ≥65 years in ChileImpacto do programa de saúde ERA e do GES na mortalidade por pneumonia adquirida na comunidade em indivíduos com idade acima de 65 anos no Chile

RESUMENObjetivo.Evaluar el impacto del Programa de Enfermedades Respiratorias del Adulto (ERA) y el Régimen General de Garantías Explícitas en Salud (GES) en la mortalidad por neumonía adquirida en la comunidad (NAC) en personas de 65 años o más en Chile.Métodos.En este estudio ecológico se calcularon las tasas anuales y trimestrales de mortalidad por NAC en personas de 65 a 79 años y de 80 años o más entre 1990 y 2014. Las fuentes de información fueron las bases de datos del Departamento de Estadística e Información de Salud y del Instituto Nacional de Estadística de Chile. Como intervenciones se evaluó el Programa ERA (puesto en marcha en el 2001) y la inclusión de la NAC en el GES (a partir del 2005). Los datos se analizaron mediante el método de series de tiempo interrumpidas, según el modelo de Prais-Winsten. Se consideró un nivel de significación del 5%.Resultados.El análisis mostró que después del inicio del programa ERA se observaron disminuciones significativas de la tasa de mortalidad por NAC en los dos grupos de edad estudiados, mientras que a partir de la incorporación de la NAC al programa GES no se encontraron cambios estadísticamente significativos en esas tasas.Conclusiones.La implementación del programa ERA contribuyó a reducir las tasas de mortalidad por NAC en personas de 65 años o más en Chile, no así la incorporación de la NAC al GES.