RXTE observations of the dipping low-mass X-ray binary 4U 1624-49

We analyse ~ 360 ks of archival data from the Rossi X-Ray Timing Explorer (RXTE) of the 21 hr orbital period dipping low-mass X-ray binary 4U 1624-49. We find that outside the dips the tracks in the colour-colour and hardness-intensity diagrams (CDs and HIDs) are reminiscent of those of atoll sources in the middle and upper parts of the banana branch. The tracks show secular shifts up to ~ 10%. We study the power spectrum of 4U 1624-49 as a function of the position in the CD. This is the first time power spectra of this source are presented. No quasi-periodic oscillations (QPOs) are found. The power spectra are dominated by very low frequency noise (VLFN), characteristic for atoll sources in the banana state, and band limited noise (BLN) which is not reliably detected but may, uncharacteristically, strengthen and increase in frequency with spectral hardness. The VLFN fits to a power law, which becomes steeper when the source moves to the harder part of the CD. We conclude that 4U 1624-49 is an atoll source which in our observations is in the upper banana branch. Combining this with the high (0.5-0.7 L_Edd) luminosity, the long-term flux stability of the source as seen with the RXTE All-Sky Monitor (ASM), and with the fact that it is an X-ray dip source, we conclude that 4U 1624-49 is most likely a GX atoll source such as GX 3+1 and GX 9+9, but seen edge on.Comment: 8 pages, 5 figures, 2 tables, accepted for publication in A&A. This version: a few typos correcte

On the Way Up? : Exploring homelessness and stable housing among homeless people in the Netherlands

Around 31,000 people in the Netherlands were literally homeless in 2015. This thesis focused on the situation of homeless people in the Netherlands and into developments in their situation over time. More insight into the situation of homeless people and into developments over time is relevant for practice and policy making and to improve the quality of life of homeless people. This thesis aimed a) to explore factors - substance use, intellectual disability and care needs - related to homelessness and their development over time among homeless people in the Netherlands, b) to investigate predictors of stable housing, and c) to explore changes in indicators of social exclusion and the association between changes in indicators of social exclusion and psychological distress. A cohort consisting of 500 homeless people in the Netherlands who reported to a central access point for social relief was followed for a period of 2.5 years. Around two-thirds of this cohort were stably housed at 2.5-year follow-up. Although being housed is an important step forward, it is a first step. To maintain a stable housing situation, progress and stability in other life domains is important. The results of the studies presented in this thesis show that the participants are on the way up, but also that ongoing support is still required

Coplanar waveguides on AlN for AlGaN/GaN MMIC applications

In this paper we present results on the characterization of Coplanar Waveguides (CPW) on AlN substrates. These transmission lines will be used in matching networks for high power Al- GaN/GaN ampliers. The large currents that will flow inside these ampliers require a large crosssectional conductor area resulting in CPW lines with large signal-to-ground spacings and/or large center conductor widths. The Line-Reflect-Line (LRL) algorithm was used in combination with a capacitance measurement to determine the transmission line parameters. It will be shown that the CPW lines with large dimensions show non-quasi- TEM behavior presumably related to parallel plate modes which influence decreases with sample thickness. The CPW lines show dispersion in the lowfrequency

Self‐reported health, healthcare service use and health‐related needs:A comparison of older and younger homeless people

The number of older homeless people with a limited life expectancy is increasing. European studies on their health‐related characteristics are lacking. This study compared self‐reported health, healthcare service use and health‐related needs of older and younger homeless people in the Netherlands. It is part of a cohort study that followed 513 homeless people in the four major Dutch cities for a period of 2.5 years, starting from the moment they registered at the social relief system in 2011. Using cross‐sectional data from 378 participants who completed 2.5‐year follow‐up, we analysed differences in self‐reported health, healthcare service use, and health‐related needs between homeless adults aged ≥50 years (N = 97) and <50 years (N = 281) by means of logistic regression. Results show that statistically significantly more older than younger homeless people reported cardiovascular diseases (23.7% versus 10.3%), visual problems (26.8% versus 14.6%), limited social support from family (33.0% versus 19.6%) and friends or acquaintances (27.8% versus 14.6%), and medical hospital care use in the past year (50.5% versus 34.5%). Older homeless people statistically significantly less often reported cannabis (12.4% versus 45.2%) and excessive alcohol (16.5% versus 27.0%) use in the past month and dental (20.6% versus 46.6%) and mental (16.5% versus 25.6%) healthcare use in the past year. In both age groups, few people reported unmet health‐related needs. In conclusion, compared to younger homeless adults, older homeless adults report fewer substance use problems, but a similar number of dental and mental problems, and more physical and social problems. The multiple health problems experienced by both age groups are not always expressed as needs or addressed by healthcare services. Older homeless people seem to use more medical hospital care and less non‐acute, preventive healthcare than younger homeless people. This vulnerable group might benefit from shelter‐based or community outreach programmes that proactively provide multidisciplinary healthcare services

Polar decompositions of quaternion matrices in indefinite inner product spaces

Polar decompositions of quaternion matrices with respect to a given indefinite inner product are studied. Necessary and sufficient conditions for the existence of an $H$-polar decomposition are found. In the process an equivalent to Witt's theorem on extending $H$-isometries to $H$-unitary matrices is given for quaternion matrices

Predicting homeless people’s perceived health after entering the social relief system in The Netherlands

Objectives: We explored whether changes in the perceived health of homeless people after entering the social relief system (SRS) in The Netherlands were predicted by housing, income, hours of work, social support, unmet care needs, arrests, physical and mental health, substance use, and experiences of autonomy, competence and relatedness, in addition to perceived health at baseline, demographics, suspected intellectual disability, the duration of homelessness and the company of children in the shelter facility. Methods: A hierarchical regression analysis was used to explore the significant predictors of the perceived health of 344 homeless persons 18 months after entering the social relief system. Results: A decrease in psychological distress and an increase in hours of (paid/voluntary) work as well as competence predicted a better perceived health. Conclusions: Perceived health is not only influenced by objective circumstances related to work and mental health, but also self-determination, as shown by the influence of competence. Services should aim to reduce psychological distress of homeless people, support them in increasing their working hours and focus on strengthening their competence

Sustainable farming with native rocks: the transition without revolution.

The development process which humanity passed through favored a series of conquests, reflected in the better quality of life and longevity, however, it also provoked upsets and severe transformation in the environment and in the human food security. Such process is driving the ecosystems to be homogeneous, and, therefore,the nutrients� supply, via nourishment. To change this panorama, the present work discusses the gains of incorporating the stonemeal technique as a strategic alternative to give back the essential fertile characteristics to the soils. This technology has the function of facilitating the rejuvenation of the soils and increasing the availability of the necessary nutrients to the full development of the plants which is a basic input for the proliferation of life in all its dimensions