Mach-Zehnder Interferometric device for spin filtering in a GaAs/AlGaAs electron gas

A spin filtering device using quantum spin interference is theoretically proposed in a GaAs/AlGaAs electron gas that has both Rashba and Dresselhaus spin-orbit couplings. The device achieves polarized electron currents by separating spin up and spin down components without a magnetic field gradient. We find two broad spin filtering regimes, one where the interferometer has symmetrical arms, where a small magnetic flux is needed to achieve spin separation, and the other with asymmetric arms where the change in path length renders an extra phase emulating the effects of a magnetic field. We identify operating points for the device where optimal electron polarization is achieved within value ranges found in a 2D electron gas. Both device setups apply for arbitrary incoming electron polarization and operate at broad energy ranges within the incoming electron band

Two-sided asymmetric subduction; implications for tectonomagmatic and metallogenic evolution of the Lut Block, Eastern Iran

West directed subduction zones show common characteristics, such as low structural elevation, deep trench, steep slab and a conjugate back-arc basin that are opposite to those of the east directed subduction zones. The tectonomagmatic and metallogenic setting of the Lut Block is still a matter of debate and several hypotheses have been put forward. Despite some authors denying the influence of the operation of Benioff planes, the majority propose that it occurred beneath the Afghan Block, while others consider that oceanic lithosphere was dragged under the Lut Block. Cu-Au porphyry deposits seem to occur in an island arc geotectonic setting during the middle Eocene while Mo-bearing deposits are coincident with the crustal thickening during Oligocene. We introduce new trace element and isotope geochemical data for granitoids and structural evidences testifying the two-sided asymmetric subduction beneath both Afghan and Lut Blocks, with different rates of consumption of oceanic lithosphere

Assinaturas isotópicas de Sr em águas minerais de Portugal e sua relação com o enquadramento geológico

This work presents the 87Sr/86Sr isotope compositions of nine samples of bottled waters from several regions of Portuguese mainland. The Sr isotopic variability displayed by the analysed waters is strongly correlated with the age and mineralogical composition of the aquifer source rocks, suggesting that the 87Sr/86Sr isotope signatures of these mineral waters are dominantly controlled by fluid-rock and/or fluid-mineral interaction processes. The lowest 87Sr/86Sr ratios are found in water samples from the Monchique aquifer (87Sr/86Sr = 0.70447), located in Late Cretaceous alkaline magmatic rocks of mantle origin. The Vimeiro waters hosted in carbonate and evaporite formations of Jurassic age have 87Sr/86Sr values of 0.70808 and appear to have reached bulk isotopic equilibrium with whole-rock, whereas the waters sourced in Cenozoic siliciclastic sediments tend to exhibit 87Sr/86Sr ratios close to the rainwater value (São Silvestre; 87Sr/86Sr = 0.71078). Finally, the waters coming from granitic and/or metamorphic terrains of the Iberian Variscan basement (Vitalis, Luso, Carvalhelhos, Fastio and Serra da Estrela) display the most radiogenic Sr isotopic signatures (87Sr/86Sr > 0.7136). In the modern commercial context, the differences encountered provide a powerful tool for fingerprinting the mineral water origin and may be used for purposes of mineral water authentication. The results obtained also show the relevance of Sr isotopes as geochemical tracers in hydrogeology.Neste trabalho, apresentam-se e discutem-se as razões isotópicas 87Sr/86Sr obtidas em nove amostras de águas engarrafadas provenientes de vários pontos do território continental português. A variabilidade isotópica encontrada nas águas analisadas relaciona-se com a idade e com a composição mineralógica das rochas do aquífero de origem, o que sugere que as razões isotópicas de Sr são fortemente controladas por processos de interacção água - rocha e/ou água - minerais. Os valores mais baixos de 87Sr/86Sr encontram-se nas águas do aquífero de Monchique (87Sr/86Sr = 0,70447), que estão associadas a ocorrências magmáticas alcalinas do Cretácico superior. As águas de Vimeiro, captadas em formações carbonatadas e evaporíticas do Mesozoico apresentam valores de 87Sr/86Sr de 0,70808, sugerindo que estas águas alcançaram o equilibrio isotópico com as rochas do aquífero, enquanto as águas associadas a rochas sedimentares siliciclásticas de idade cenozóica possuem razões isotópicas muito próximas dos valores que se encontram na água da chuva (São Silvestre; 87Sr/86Sr = 0,71078). Por último, as águas procedentes de rochas graníticas e/ou metamórficas do soco varisco (Vitalis, Luso, Carvalhelhos, Fastio e Serra da Estrela) apresentam composições isotópicas de Sr mais radiogénicas (87Sr/86Sr > 0,7136). Num contexto comercial as diferenças encontradas proporcionam uma ferramenta que poderá ser usada para fins de certificação da proveniência de águas minerais. Os resultados obtidos também mostram a importância dos isótopos de Sr como traçadores geoquímicos em hidrogeologia

Fluid inclusion geothermometry of various alteration – mineralization zones of Chah-shaljami prospect, Eastern Iran

منطقه اکتشافي چاهشلغمي در خراسان جنوبي و در کمربند آتشفشاني – نفوذي بلوک لوت قرار گرفته است. تودههاي نيمه عميق گرانيتوئيدي مربوط به اليگوسن، درون تواليهاي آتشفشاني - پيروکلاستيک ائوسن نفوذ کردهاند. انواع کانيهاي دگرساني شامل آلونيت، ژاروسيت، کلريت، ديکيت، سريسيت، مونتموريلونيت، کوارتز و اکسيدهاي آهن شناسايي شدهاند. کانيسازي شامل پيريت، آرسنوپيريت، موليبدنيت، کالکوپيريت، اسفالريت، گالن و انارژيت است. ميزان دما و شوري بالاي سيالات درگير در زون دگرساني سيليس - کلريت ميتواند در تعيين مرکز سيستم کانيسازي در اکتشافات بعدي مورد استفاده قرار گيرد. دما و شوري سيالات به سمت زون دگرساني کوارتز حفرهاي در حال کاهش است که احتمالا نشان دهنده افزايش دخالت آبهاي جوي ميباشد. شواهد زمينشناسي، دگرساني، کانيسازي و تحول سيالات هيدروترمال نشان دهنده کانيسازي اپيترمال سولفيداسيون بالا مرتبط با سيستم پورفيري عمقي در منطقه ميباشد. کليد واژهها: بلوک لوت، آلونيت، سيالات درگير، اپيترمال.Chah-shaljami exploration area is located in the Southern Khorasan and belongs to the Lut Block volcanic-plutonic belt. Oligocene subvolcanic granitoids intruded into Eocene volcanic - volcaniclastic sequences. Alteration minerals include alunite, jarusite, chlorite, dickite, sericite, montmorillonite, quartz and iron oxide. Mineralization includes pyrite, arsenopyrite, molybdenite, chalcopyrite, sphalerite, galena and enargite. High temperature – salinity of fluid inclusions from sericite alteration is an indicator that can direct the next exploration toward the mineralization center. Temperature – salinity of fluid inclusions decrease toward the vuggy quartz alteration which indicate the increase of the role of meteoric fluids. The gathered data on alteration, mineralization and hydrothermal fluids together with field evidence evidence indicate that the high-sulfidation epithermal mineralization is related to the deep porphyry system in the area

Hydrothermal fluids evolution from various alteration – mineralization zones of Dehsalm porphyry type system, Lut block, Eastern Iran

منطقه اکتشافي دهسلم در خراسان جنوبي و در کمربند آتشفشاني – نفوذي بلوک لوت قرار گرفته است. تودههاي نيمه عميق حدواسط تا اسيدي مربوط به اليگوسن، درون تواليهاي آتشفشاني، ماسهسنگ و سيلتستون ائوسن نفوذ کردهاند. زونهاي دگرساني شامل انواع پتاسيک، پروپليتيک، سريسيت- رسي، اپيدوتي، سريسيت - کلسيت - سيليس و سيليسي ميباشند. کانيسازي بصورت رگه – رگچهاي و پراکنده شامل مگنتيت، پيريت، موليبدنيت، کالکوپيريت، بورنيت، طلا، آرسنوپيريت، اسفالريت، گالن، کوليت، ديژنيت و کانيهاي سولفوسالت ميباشد. مطالعه سيالات درگير تاثير فرايندهاي جوشش، ناآميختگي، سرد شدن و رقيق شدگي توسط آيهاي جوي را طي تحول سيالات کانهساز نشان داده است. ميزان دما و شوري سيالات درگير از زون دگرساني پتاسيک به سمت زون دگرساني سريسيتي - رسي در حال کاهش است که احتمالا نشان دهنده افزايش دخالت آبهاي جوي ميباشد. شواهد زمينشناسي، دگرساني، کاني- سازي و تحول سيالات هيدروترمال نشان دهنده کانيسازي سيستم پورفيري در منطقه ميباشد. کليد واژهها: بلوک لوت، سيالات درگير، جوشش، سيستم پورفيريDehsalm exploration area is located in the Southern Khorasan and belongs to the Lut Block volcanic-plutonic belt of the Lut block. Oligocene intermediate to acidic subvolcanic rocks intruded into Eocene volcanic, sandstone and siltstone sequences. Alteration zones include potassic, propylitic, sericite – calcite – silica, sericite – argillic, epidote and silicification. Vein – veinlet and disseminated mineralization comprise magnetite, pyrite, molybdenite, chalcopyrite, bornite, arsenopyrite, sphalerite, galena, covellite, digenite and sulfosalts. Fluid inclusion studies have shown the affect of boiling, fluid immiscibility, cooling and dilution processes by meteoric fluids during the evolution of mineralizing fluids. Temperature – salinity of fluid inclusions decrease from potassic through sericite – argillic alteration which indicate the increase of the role of meteoric fluids. The gathered data on alteration, mineralization and hydrothermal fluids together with field evidence indicate that a porphyry type mineralization system occurs in the area

Warm CO in evolved stars from the THROES catalogue. II. Herschel/PACS spectroscopy of C-rich envelopes

This is the second paper of a series making use of Herschel/PACS spectroscopy of evolved stars in the THROES catalogue to study the inner regions of their circumstellar envelopes (CSEs). We analyze the CO emission spectra, including a large number of high-$J$ CO lines (from $J$=14-13 to $J$=45-44), as a proxy for the warm molecular gas in the CSEs of a sample of bright carbon-rich stars spanning different evolutionary stages from the Asymptotic Giant Branch (AGB) to the young planetary nebulae (PNe) phase. We use the rotational diagram (RD) to derive rotational temperatures ($T_{\rm rot}$) and masses ($M_{\rm H_2}$) of the envelope layers where the CO transitions arise. We also obtain a first order estimate of the mass-loss rates and assess the impact of the opacity correction for a range of characteristic envelope radii. We use multi-epoch spectra for the well studied C-rich envelope IRC+10216 to investigate the impact of CO flux variability on the values of $T_{\rm rot}$ and $M_{\rm H_2}$. PACS sensitivity allowed the study of higher rotational numbers than before, indicating the presence of a significant amount of warmer gas ($\sim$200-900 K) not traceable with lower-$J$ CO observations at sub-mm/mm wavelengths. The masses are in the range $\sim10^{-2}-10^{-5}\,\rm M_{\odot}$, anti-correlated with temperature. For some strong CO emitters we infer a double temperature (warm $T_{\rm rot}\sim$400 K and hot $T_{\rm rot}\sim$820 K) component. From the analysis of IRC+10216, we corroborate that the effect of line variability is perceptible on the $T_{\rm rot}$ of the hot component only, and certainly insignificant on $M_{\rm H_2}$ and, hence, the mass-loss rate. Therefore, the parameters derived from the RD are robust even when strong line flux variability occurs, with the major source of uncertainty in the estimate of the mass-loss rate being the size of the CO-emitting volume.Comment: accepted in A&

Single-Layer Cubipod Armored Breakwaters in Punta Langosteira (Spain)

This paper describes the design process, hydraulic stability tests and construction of two single-layer Cubipod armored breakwaters in the Port of Punta Langosteira (A Coruña, Spain), located on the Atlantic coast of Spain, the first single-layer armors of randomly placed massive concrete armor units. The environmental, geotechnical, economic and logistic conditions favored randomly-placed Cubipods in single-layer armoring. 3D hydraulic stability tests of single-layer Cubipod armored breakwaters proved useful to validate the final design with 15-tonne and 25-tonne Cubipod units

Quantitative analysis of the effects of incorporating laser powder bed fusion manufactured conformal cooling inserts in steel moulds over four types of defects of a commercially produced injected part

The introduction of additively manufactured conformal cooling inserts in steel moulds for plastic injection is becoming a recommended standard. Fine adjustment of the temperatures in the mould has demonstrated potential to reduce cycle times and to increase production volumes. Within this context, the present article explores the historical production data of a commercially produced part, before and after the incorporation of an LPBF conformal cooling insert, to analyse what is the quantitative real effect on the efficiency of the production runs. The article analyses the change in the global rejection rates, and its effect over four different product defect types, i.e.: optical (surface), part integrity (bubbles, transparency, geometry), incomplete fill-in (interior), and breakages during extraction. The results demonstrate a specific decrease on the average appearance (from 20.53% to 13.48%; reduction of 7.05%) and variability (standard deviation from 14.16% to 6.81%; reduction of a 7.35%), of the global scrap rates, and a significant decrease in the scrap rates generated by optical defects and extraction part breakages. The article also characterises the former and the new processes by adjusting two distribution functions (Pareto Type-I and Weibull) and compares different estimates for the global expected scrap rates in past and future production runs.Peer ReviewedPostprint (published version

Orthopedic surgery increases atherosclerotic lesions and necrotic core area in ApoE-/- mice

Background and aims Observational studies show a peak incidence of cardiovascular events after major surgery. For example, the risk of myocardial infarction increases 25-fold early after hip replacement. The acuteness of this increased risk suggests abrupt enhancement in plaque vulnerability, which may be related to intra-plaque inflammation, thinner fibrous cap and/or necrotic core expansion. We hypothesized that acute systemic inflammation following major orthopedic surgery induces such changes. Methods ApoE−/− mice were fed a western diet for 10 weeks. Thereafter, half the mice underwent mid-shaft femur osteotomy followed by realignment with an intramedullary K-wire, to mimic major orthopedic surgery. Mice were sacrificed 5 or 15 days post-surgery (n = 22) or post-saline injection (n = 13). Serum amyloid A (SAA) was measured as a marker of systemic inflammation. Paraffin embedded slides of the aortic root were stained to measure total plaque area and to quantify fibrosis, calcification, necrotic core, and inflammatory cells. Results Surgery mice showed a pronounced elevation of serum amyloid A (SAA) and developed increased plaque and necrotic core area already at 5 days, which reached significance at 15 days (p = 0.019; p = 0.004 for plaque and necrotic core, respectively). Macrophage and lymphocyte density significantly decreased in the surgery group compared to the control group at 15 days (p = 0.037; p = 0.024, respectively). The density of neutrophils and mast cells remained unchanged. Conclusions Major orthopedic surgery in ApoE−/− mice triggers a systemic inflammatory response. Atherosclerotic plaque area is enlarged after surgery mainly due to an increase of the necrotic core. The role of intra-plaque inflammation in this response to surgical injury remains to be fully elucidated. © 2016 Elsevier Ireland Lt

Does posterior capsule opacification affect the results of diagnostic technologies to evaluate the retina and the optic disc?

The visual outcome obtained after cataract removal may progressively decline because of posterior capsular opacification (PCO). This condition can be treated by creating an opening in the posterior lens capsule by Nd:YAG laser capsulotomy. PCO optical imperfections cause several light reflection, refraction, and diffraction phenomena, which may interfere with the functional and structural tests performed in different ocular locations for the diagnosis and follow-up of ocular disease, like macular and optic nerve diseases. Some parameters measured by visual field examinations, scanning laser polarimetry, and optical coherence tomography (OCT) have changed after PCO removal. Imaging quality also changes following capsulotomy. Consequently, the results of ancillary tests in pseudophakic eyes for studying ocular diseases like glaucoma or maculopathies should be correlated with other clinical examinations, for example, slit-lamp biomicroscopy or funduscopy. If PCO is clinically significant, a new baseline should be set for future comparisons following capsulotomy when using automated perimetry and scanning laser polarimetry. To perform OCT in the presence of PCO, reliable examinations (considering signal strength) apparently guarantee that measurements are not influenced by PCO