The boundary layer thickness on a compressor blade suction surface increases rapidly under a adverse pressure gradient and even separates from the blade surface. This paper proposes a novel method for developing the slot inside the blade, with the inlet of the slot located at the leading edge of the blade and the outlet located at the suction surface, using the momentum of the incoming flow to form a high velocity jet to control the boundary layer on the suction surface. For a plane cascade with a diffusion factor of 0.45, the effects of the main slot parametres (such as the shape of the slot and the positions of the slot inlet and outlet) on the flow in the slot, the flow field and the aerodynamic performance of the cascade were investigated with a numerical method. When the aerodynamic performance of cascades with slotted and unslotted blades was compared, it was found that a reasonable slot structure can effectively inhibit the development of the boundary layer on the blade suction surface and greatly improve the aerodynamic performance of the cascade. Based on the influence of the slot parametres of the above cascade, the slot of a plane cascade with a diffusion factor of 0.60 was designed. The numerical calculation results show that the slotted cascade with a diffusion factor of 0.60 outperformed the slotted cascade with a diffusion factor of 0.45. This result showed that the higher the cascade load, the greater the performance improvement from slotting. Furthermore, the unslotted and slotted cascades were tested, and the test results agreed well with the calculations. The aerodynamic performance of the slotted cascade was better than that of the unslotted cascade, which verifies the accuracy of the calculation method and the feasibility of blade slotting for suppressing the development of boundary layers on suction surfaces and reducing flow loss.

Youth's academic and emotional functioning are closely related, yet little is known about the timing and direction of relationships involving internalizing problems, which are characterized by over control of emotions, anxiety, and depression as well as multiple aspects of academic achievement. This study addresses these gaps using data from the Study of Early Child Care and Youth Development (N = 1,048) to examine the processes by which problems in one domain of functioning lead to problems in another, known as a “cascade effect.” Results of longitudinal structural equation modeling indicate (a) a direct and indirect negative cascade effect from girls’ internalizing problems to their school achievement in high school, (b) a positive contemporaneous association of 9th grade boys’ internalizing problems with their cognitive achievement; and (c) ways in which demographic characteristics and adolescent social and maturational processes account for variation in functioning yet do not alter the processes by which the emotional and academic functioning interact. Results are discussed with regard to identifiying adolescents’ internalizing problems, gender differences in the effects of internalizing problems on academic functioning, timing of evidence-based interventions, and implications for mental health promotion among girls.

Migrants are considered a key group at risk for HIV infection. This study describes differences between migrants and the Spanish-born population as they progress through the HIV care cascade in Catalonia, Spain. This study found that among people reached by prevention activities, migrants had a higher number of barriers to access HIV testing services than Spanish-born people, driven primarily by shared risk factors. Between 2001 and 2013, 9829 new HIV diagnoses were reported in Catalonia, the proportion of migrants increasing from 24% in 2001 to 41% in 2013. Compared with Spanish-born people, migrants had a higher proportion of women at diagnosis (24·6% vs. 16·7%), and were younger (median age of 33 vs. 37). The most frequent at-risk population was MSM (men who have sex with men) in both migrants and Spanish-born people, (40% and 43%, respectively), although there were significant differences by region of origin. People from sub-Saharan Africa had the highest proportion of late diagnosis (63·7%). Compared with the Spanish-born population, migrants on follow-up had a lower proportion of people on antiretroviral therapy (ART) (93·7% vs. 90·8%, P < 0·001) and with viral suppression (87·2% vs. 82·9%, P < 0·001). Migrants have higher number of barriers to access HIV testing services, lower retention rates and proportions on ART as compared with Spanish-born people, these differences not being uniform between migrants from different regions.

Research in psychiatry could speeden its progress by taking the manifest heterogenity and variability of symptom expression within diagnostic groups more fully into account. Since Kraepelin symptom variation has been recognized to have both biological and environmental roots. If investigated systematically, such variations in illness experience will yield new subtypes that will provide greater insight into the onset, course and vulnerability of mental disorders. Studies ranging from population surveys to the laboratory have demonstrated that psychopathology is not randomly distributed in a population, nor is it constantly present in the lives of individuals. At both the population and the person levels, psychopathology varies with time and place. At the population level, illness processes localize in risk groups, who often reside in specific neighbourhoods or social settings. The individual experience of psychopathology also fluctuates with time, place and culture. This variability requires methods for case detection and treatment planning that take this into account.

In this work, the design of the wideband millimeter-wave power amplifier for multiband communication is presented. In order to achieve compact, simple and robust design, a differential cascade transformer-coupled topology is used. The amplifier is implemented in 90 nm low-leakage CMOS technology and achieves 3 dB bandwidth of 8 GHz (from 60 to 68 GHz) and a peak gain of 18 dB. The PO1dB is better than 5 dBm from 58 to 80 GHz, and peak output power is 11.9 dBm with 1 dB flatness from 62 to 77 GHz. The chip consumes an area of 0.25 mm2 including bond pads and DC current of 125 mA from a 2.2 V supply.