Mitigating Electronic Current in Molten Flux for the Magnesium SOM Process

The solid oxide membrane (SOM) process has been used at 1423 K to 1473 K (1150 °C to 1200 °C) to produce magnesium metal by the direct electrolysis of magnesium oxide. MgO is dissolved in a molten MgF[subscript 2]-CaF[subscript 2] ionic flux. An oxygen-ion-conducting membrane, made from yttria-stabilized zirconia (YSZ), separates the cathode and the flux from the anode. During electrolysis, magnesium ions are reduced at the cathode, and Mg[subscript (g)] is bubbled out of the flux into a separate condenser. The flux has a small solubility for magnesium metal which imparts electronic conductivity to the flux. The electronic conductivity decreases the process current efficiency and also degrades the YSZ membrane. Operating the electrolysis cell at low total pressures is shown to be an effective method of reducing the electronic conductivity of the flux. A two steel electrode method for measuring the electronic transference number in the flux was used to quantify the fraction of electronic current in the flux before and after SOM process operation. Potentiodynamic scans, potentiostatic electrolyses, and AC impedance spectroscopy were also used to characterize the SOM process under different operating conditions.National Science Foundation (U.S.) (Grant No. 102663)United States. Dept. of Energy (Grant No. DE-EE0005547

Theory of the thermoelectricity of intermetallic compounds with Ce or Yb ions

The thermoelectric properties of intermetallic compounds with Ce or Yb ions are explained by the single-impurity Anderson model which takes into account the crystal-field splitting of the 4{\it f} ground-state multiplet, and assumes a strong Coulomb repulsion which restricts the number of {\it f} electrons or {\it f} holes to $n_f\leq 1$ for Ce and $n_f^{hole}\leq 1$ for Yb ions. Using the non-crossing approximation and imposing the charge neutrality constraint on the local scattering problem at each temperature and pressure, the excitation spectrum and the transport coefficients of the model are obtained. The thermopower calculated in such a way exhibits all the characteristic features observed in Ce and Yb intermetallics. Calculating the effect of pressure on various characteristic energy scales of the model, we obtain the $(T,p)$ phase diagram which agrees with the experimental data on CeRu$_{2}$Si$_2$, CeCu$_{2}$Si$_2$, CePd$_{2}$Si$_2$, and similar compounds. The evolution of the thermopower and the electrical resistance as a function of temperature, pressure or doping is explained in terms of the crossovers between various fixed points of the model and the redistribution of the single-particle spectral weight within the Fermi window.Comment: 13 pages, 11 figure

Does rumination mediate the relationship between emotion regulation ability and posttraumatic stress disorder?

Background and objectives: Trauma-related rumination has been suggested to be involved in the maintenance of posttraumatic stress disorder (PTSD). This view has empirically been supported by extensive evidence using cross-sectional, prospective, and experimental designs. However, it is unclear why trauma survivors engage in rumination despite its negative consequences. The current study aimed to explore the hypothesis that low emotion regulation ability underlies trauma-related rumination. Methods: Emotion regulation ability and trauma-related rumination were assessed in 93 road traffic accident survivors 2 weeks post-trauma. In addition, symptom levels of PTSD were assessed at 2 weeks as well as 1, 3, and 6 months follow-up. Results: Emotion regulation ability was significantly related to trauma-related rumination as well as levels of PTSD symptoms. In addition, the association between low emotion regulation ability and PTSD was mediated by rumination. Conclusions: The findings support the view that rumination is used as a dysfunctional emotion regulation strategy by trauma survivors

First order phase transition from ferromagnetism to antiferromagnetism in Ce(Fe0.96_{0.96}Al0.04_{0.04})2_2

Taking the pseudobinary C15 Laves phase compound Ce(Fe$_{0.96}$Al$_{0.04}$)$_2$ as a paradigm for studying a ferromagnetic to antiferromagnetic phase transition, we present interesting thermomagnetic history effects in magnetotransport as well as magnetisation measurements across this phase transition. A comparison is made with history effects observed across the ferromagnetic to antiferromagnetic transition in R$_{0.5}$Sr$_{0.5}$MnO$_3$ crystals.Comment: 11 pages of text and 4 figures; submitted to Physical Review Letter

Conformity Motives For Alcohol Use Are Associated With Risky Sexual Behavior Among Alcohol-Dependent Patients In Residential Substance Abuse Treatment

Alcohol misuse is associated with a variety of negative outcomes, including risky sexual behavior (RSB). In an attempt to better identify the subset of individuals at greatest risk for these negative outcomes, a growing body of research has begun to examine the role of alcohol use motives in risk for alcohol use-related negative outcomes. Although the majority of research in this area has focused on coping motives, conformity motives may be particularly relevant to outcomes such as RSB. Specifically, conformity motives may operate as a proxy risk factor for RSB, reflecting the tendency to engage in interpersonally-oriented risk behaviors in order to avoid rejection, interpersonal conflict, or social ostracism. Therefore, the current study examined the relation between conformity motives for alcohol use and RSB in a sample of 94 patients in a residential substance abuse treatment center. Results indicated that conformity motives were associated with RSB above and beyond other motives for alcohol use, as well as relevant covariates. Findings support the notion that conformity motives may operate as a proxy risk factor that could assist in identifying individuals at elevated risk for engaging in RSB

Fermi-liquid instabilities at magnetic quantum phase transitions

This review discusses instabilities of the Fermi-liquid state of conduction electrons in metals with particular emphasis on magnetic quantum critical points. Both the existing theoretical concepts and experimental data on selected materials are presented; with the aim of assessing the validity of presently available theory. After briefly recalling the fundamentals of Fermi-liquid theory, the local Fermi-liquid state in quantum impurity models and their lattice versions is described. Next, the scaling concepts applicable to quantum phase transitions are presented. The Hertz-Millis-Moriya theory of quantum phase transitions is described in detail. The breakdown of the latter is analyzed in several examples. In the final part experimental data on heavy-fermion materials and transition-metal alloys are reviewed and confronted with existing theory.Comment: 62 pages, 29 figs, review article for Rev. Mod. Phys; (v2) discussion extended, refs added; (v3) shortened; final version as publishe

Pathogens that cause acute febrile illness among children and adolescents in Burkina Faso, Madagascar and Sudan

BACKGROUND: The etiology and optimal clinical management of acute febrile illness (AFI) is poorly understood. METHODS: Blood samples taken from study participants with acute fever (>/=37.5 degrees C) or a history of fever and recruited into the previous Typhoid-Fever-Surveillance-in-Africa (TSAP) study were evaluated using a polymerase chain reaction (PCR)-based TaqMan-Array Card designed to detect a panel of bacterial, viral and parasitic pathogens. Clinical metadata were also assessed. RESULTS: A total of 615 blood samples available for analysis originated from Burkina Faso (n=53), Madagascar (n=364) and Sudan (n=198) and were taken from participants ranging from 0-19 years of age. Most individuals [86.4% (531/615)] presenting at healthcare facilities were outpatient adolescents (11-19 years-old). Leading clinical diagnoses were respiratory tract infections [45.9% (282/615)], malaria [27.3% (168/615)], and gastrointestinal tract infections [10.7% (66/615)]. Through the TaqMan-Array Card, at least one pathogen was detected in 62% (33/53), 24% (86/364), and 60% (118/198) of specimens, from Burkina Faso, Madagascar and Sudan, respectively. The leading identified pathogen overall was Plasmodium spp., accounting for 47% (25/53), 2.2% (8/364) and 45% (90/198) of AFI at respective sites. In Madagascar, dengue virus was the most prevalent pathogen (10.2%). Overall, 69% (357/516) of patients with clinical diagnoses of malaria, respiratory, or gastrointestinal infections were prescribed a WHO-guideline-recommended empiric antibiotic,whereas only 45% (106/237) of patients with pathogens detected were treated with an antibiotic exerting likely activity. CONCLUSIONS: A PCR-approach for identifying multiple bacterial, viral and parasitic pathogens in whole blood unveiled a diversity of previously undetected pathogens in AFI cases and carries implications for the appropriate management of this common syndrome

Assessment of the revised Difficulties in Emotion Regulation Scales among adolescents and adults with severe mental illness

The Difficulties in Emotion Regulation Scale (DERS) comprising 36 items has been widely used across age, gender, psychopathology, language, and culture. Recently several alternative abridged forms have been introduced, namely, the DERS-16 (Bjureberg et al. 2016), the DERS-SF (Kaufman et al. 2016), and the DERS-18 (Victor and Klonsky, 2016), each composed of 16 or 18 items, to provide researchers and clinicians with a shorter measure of emotion dysregulation. However, no study to date has directly compared the psychometrics of these alternative forms. In the present study, using confirmatory factor analysis we first examined the factor structure of the four models of the DERS in two inpatient samples of 636 adolescents in the age-range of 12–17 years (M = 15.33, SD = 1.43), and 1807 adults in the age-range of 18–76 years (M = 34.86, SD = 14.63) with severe mental illness. Next, measurement invariance was tested comparing the two age groups across the four models of DERS. Only the DERS-SF established metric and scalar measurement invariance. Findings suggest that the factor structure of the original and the abridged models of DERS have acceptable fit, however only DERS-SF had equivalence of factor loadings and item intercepts across adolescents and adults

Emotion dysregulation mediates the relationship between nightmares and psychotic experiences: Results from a student population

Sleep-disruption is commonly associated with psychotic experiences. Whilst sparse, the literature to date highlights nightmares and related distress as prominent risk factors for psychosis in students. We aimed to further explore the relationship between specific nightmare symptoms and psychotic experiences in university students whilst examining the mediating role of emotion dysregulation. A sample (N=1273) of student respondents from UK universities completed measures of psychotic experiences, nightmare disorder symptomology, and emotion dysregulation. Psychotic experiences were significantly more prevalent in students reporting nightmares (n=757) relative to those who did not (n=516). Hierarchical linear regression analysis showed that psychotic experiences were significantly associated (Adjusted R2 = 32.4%) with perceived nightmare intensity, consequences and resulting awakenings, and with emotion regulation difficulties. Furthermore, multiple mediation analysis showed that the association between psychotic experiences and nightmare factors was mediated by emotion regulation difficulties. Adaptive regulation of dream content during rapid eye-movement sleep has previously been demonstrated to attenuate surges in affective arousal by controlling the intensity and variability of emotional content. Difficulties in emotion regulation may partially explain the experience of more intense and disruptive nightmares amongst individuals with psychotic experiences. Emotion regulation may represent an important control mechanism that safeguards dream content and sleep quality