Combination of an electrolytic pretreatment unit with secondary water reclamation processes

The design and fabrication of a flight concept prototype electrolytic pretreatment unit (EPU) and of a contractor-furnished air evaporation unit (AEU) are described. The integrated EPU and AEU potable water recovery system is referred to as the Electrovap and is capable of processing the urine and flush water of a six-man crew. Results of a five-day performance verification test of the Electrovap system are presented and plans are included for the extended testing of the Electrovap to produce data applicable to the combination of electrolytic pretreatment with most final potable water recovery systems. Plans are also presented for a program to define the design requirements for combining the electrolytic pretreatment unit with a reverse osmosis final processing unit

Critical-state effects on microwave losses in type-II superconductors

We discuss the microwave energy losses in superconductors in the critical state. The field-induced variations of the surface resistance are determined, in the framework of the Coffey and Clem model, by taking into account the distribution of the vortex magnetic field inside the sample. It is shown that the effects of the critical state cannot generally be disregarded to account for the experimental data. Results obtained in bulk niobium at low temperatures are quantitatively justified.Comment: 4 pages, 4 embedded figures, to be published on Eur. Phys. J.

Field-induced suppression of the pi-band superconductivity and magnetic hysteresis in the microwave surface resistance of MgB_2 at temperatures near T_c

We report on the magnetic-field-induced variations of the microwave surface resistance, R_s, in a polycrystalline MgB_2 sample, at different values of temperature. We have detected a magnetic hysteresis in R_s, which exhibits an unexpected plateau on decreasing the DC magnetic field below a certain value. In particular, at temperatures near T_c the hysteresis manifests itself only through the presence of the plateau. Although we do not quantitatively justify the anomalous shape of the magnetic hysteresis, we show that the results obtained in the reversible region of the R_s(H) curve can be quite well accounted for by supposing that, in this range of magnetic field, the pi-gap is almost suppressed by the applied field and, consequently, all the pi-band charge carriers are quasiparticles. On this hypothesis, we have calculated R_s(H) supposing that fluxons assume a conventional (single core) structure and the flux dynamics can be described in the framework of conventional models. From the fitting of the experimental results, we determine the values of H_{c2}^pi(T) at temperatures near T_c. In our opinion, the most important result of our investigation is that, at least at temperatures near T_c, the value of the applied field that separates the reversible and irreversible regions of the R_s(H) curves is just H_{c2}^pi(T); a qualitative discussion of the possible reason of this finding is given.Comment: 20 pages, 8 embedded figures, 2 Appendices, accepted for publication in Supercond. Sci. Techno

Depinning frequency in a heavily neutron-irradiated MgB2 sample

The magnetic-field-induced variations of the microwave surface resistance have been investigated in a heavily neutron-irradiated MgB2 sample, in which the irradiation has caused the merging of the two gaps into a single value. The experimental results have been analyzed in the framework of the Coffey and Clem model. By fitting the experimental data, we have determined the field dependence of the depinning frequency, omega_0, at different values of the temperature. Although the pinning is not particularly effective, the value of omega_0 obtained at low temperatures is considerably higher than that observed in conventional low-temperature superconductors.Comment: 15 pages, 6 figures; to be published in Physica

From Hooah to Om : Mindfulness Practices for a Military Population

Mindfulness practices, in general, have a growing body of evidence of effectiveness for improving both physical health and mental health. Further, these practices are showing promise when implemented with military populations for mental health issues such as PTSD. Challenges arise for practitioners in understanding the military\u27s cultural differences and the functional aspects of mindfulness that may be specifically useful to military members. We outline strategies for referring military members to quality services and instruction, as well as best practices for connecting with military clients. Recommendations are made for further research with female service members and using single case design

Microwave surface resistance of pristine and neutron-irradiated MgB2 samples in magnetic field

We report on the microwave surface resistance of two polycrystalline Mg11B2 samples; one consists of pristine material, the other has been irradiated at very high neutron fluence. It has already been reported that in the strongly irradiated sample the two gaps merge into a single value. The mw surface resistance has been measured in the linear regime as a function of the temperature and the DC magnetic field, at increasing and decreasing fields. The results obtained in the strongly irradiated sample are quite well justified in the framework of a generalized Coffey and Clem model, in which we take into account the field distribution inside the sample due to the critical state. The results obtained in the pristine sample show several anomalies, especially at low temperatures, which cannot be justified in the framework of standard models for the fluxon dynamics. Only at temperatures near Tc and for magnetic fields greater than 0.5Hc2(T) the experimental data can quantitatively be accounted for by the Coffey and Clem model, provided that the upper-critical-field anisotropy is taken into due account.Comment: RevTeX, 13 pages with 10 eps figures, in press on EPJ

Fluxon dynamics in Li-Al codoped MgB2 by microwave surface resistance measurements

The magnetic-field-induced variations of the microwave surface resistance, R_s, have been investigated in ceramic Mg_{1-x}(LiAl)_xB_2, with x in the range 0.1 - 0.4. The measurements have been performed on increasing and decreasing the DC magnetic field, H_0, at fixed temperatures. At low temperatures, we have observed a magnetic hysteresis in the R_s(H_0) curves in all the investigated samples. On increasing the temperature, the range of H_0 in which the hysteretic behavior is visible shrinks; however, in the sample with x = 0.1 it is present up to temperatures close to T_c. We show that the field dependence of R_s can be quantitatively justified taking into account the critical-state effects on the fluxon lattice only in the sample with x = 0.4. On the contrary, in the samples with x < 0.4 the hysteresis exhibits an unusual shape, similar to that observed in others two-gap MgB_2 samples, which cannot be justified in the framework of the critical-state models.Comment: 8 pages, 3 embedded figures; proceedings of the Sixth International Conference on Vortex Matter in Nanostructured Superconductors (VORTEX VI) 17-24 September 2009, Rhodes, Greec

Fluxon dynamics by microwave surface resistance measurements in MgB2

Field-induced variations of the microwave surface resistance, Rs(H), have been investigated in high-density ceramic MgB2. At low temperatures, several peculiarities of the Rs(H) curves cannot be justified in the framework of models reported in the literature. We suggest that they are ascribable to the unconventional vortex structure in MgB2, related to the presence of two gaps. On the contrary, the results near Tc can be accounted for by the Coffey and Clem model, with fluxons moving in the flux-flow regime, provided that the anisotropy of the upper critical field is taken into due account.Comment: 6 pages, 4 figure

Electromagnetic response of LaO_0.94F_0.06FeAs: AC susceptibility and microwave surface resistance

We discuss on the electromagnetic response of a polycrystalline sample of LaO_0.94F_0.06FeAs exposed to DC magnetic fields up to 10 kOe. The low- and high-frequency responses have been investigated by measuring the AC susceptibility at 100 kHz and the microwave surface resistance at 9.6 GHz. At low as well as high DC magnetic fields, the susceptibility strongly depends on the amplitude of the AC driving field, highlighting enhanced nonlinear effects. The field dependence of the AC susceptibility exhibits a magnetic hysteresis that can be justified considering the intragrain-field-penetration effects on the intergrain critical current density. The microwave surface resistance exhibits a clockwise magnetic hysteresis, which cannot be justified in the framework of the critical-state models of the Abrikosov-fluxon lattice; it may have the same origin as that detected in the susceptibility.Comment: 8 pages, 4 embedded eps figures; Proceedings of the 9th EUCAS Conference (Dresden, Germany, September 13-17, 2009

La sorveglianza della tubercolosi in Sicilia

Obiettivi. Descrivere l’andamento dei casi di tubercolosi (TB) in Sicilia negli anni 2010-2013. Disegno e partecipanti. Indagine osservazionale delle notifiche di TB relative agli anni 2010-2013 mediante l’analisi dei dati del Sistema informativo delle malattie infettive (SIMI) e indagine epidemiologico-molecolare mediante tipizzazione spoligo- e 24- loci mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) dei ceppi di Mycobacterium tuberculosis complex (MTBC) isolati a Palermo negli anni 2012-2013. Risultati. Negli anni 2010-2013 sono stati notificati in Sicilia 876 casi di TB con un tasso medio annuale di notifica pari a 4,4 casi per 100.000 abitanti. La proporzione di casi di TB in soggetti nati all’estero è crescente e nel 2012 e 2013 supera quella nella popolazione autoctona. L’età mediana dei pazienti stranieri è risultata significativamente inferiore agli italiani (30,5 vs. 51,2 anni, p <0,001). La distribuzione per classi di età è stata significativamente differente nelle due subpopolazioni, con la proporzione più elevata di casi nelle fascia di età 15-44 anni tra gli stranieri e, al contrario, una distribuzione uniforme dei pazienti italiani tra le fasce di età 15-44, 45-64 e >64 anni. Nell’82,5% dei casi è stata diagnosticata una localizzazione polmonare. La tipizzazione molecolare è stata effettuata su 151 ceppi di MTBC. Mediante spoligotyping essi sono stati attribuiti a 14 differenti lineage e 33 sublineage rappresentati con frequenza diversa tra le due subpopolazioni di pazienti. Soltanto nove ceppi (6,2%) sono stati inclusi in quattro cluster. Sono stati identificati, infine, due ceppi multiresistenti. Conclusioni. L’epidemiologia della TB in Sicilia è complessa e in rapida evoluzione, con una crescente proporzione di casi in soggetti non italiani e una grande eterogeneità dei ceppi di MTBC circolanti. L’integrazione di strumenti convenzionali e molecolari è necessaria per una sorveglianza efficace e un’interpretazione accurata dell’epidemiologia della TB in Sicilia