The angular scattered-light intensity, or scattering curve, for a spherical particle is known to display approximate power-law structures when formulated in terms of the scattering wave vector and ...plotted in log–log scale. Empirically based studies reveal that the structures have common behavior across a wide variety of particle size and refractive index. These patterns, as they are called, are useful as they can relate the scattering curve to particle properties in some cases. The cause of the patterns, however, has not been satisfactorily derived from first principles until recently and the formal analysis has yet to be applied to nonspherical particles. This paper reviews the patterns for spherical particles and shows how they can be derived from the Maxwell equations for weakly refracting particles. The derivation is then extended to spheroidal particles where similar patterns are seen. A graphically based technique is used to show how interference between particular regions within a particle can account for so-called crossovers, which are transitions from one power-law to another in a given curve. Application of the phasor analysis to strongly refractive spheres and spheroids demonstrates that the interference interpretation remains valid despite the absence of a direct analytical derivation from the Maxwell equations. Finally, several laboratory experiments are discussed that demonstrate how the patterns are seen in measurements and how they may be used in practice to size particles.
► Power-law patterns in scattering from spherical particles is reviewed. ► New patterns for nonspherical particles are discussed. ► The patterns are derived from first principles. ► Explanations for the patterns are given and interpreted. ► Laboratory measurements displaying the patterns are discussed.
Baghouse dust collectors are using in the drying unit of Beni Idir situated in Beni-Idir Khouribga city, Morocco, to retrieve phosphates particles from dust air-drying before its expulsion through ...the smokestacks. The phosphate dust samples used in this study were taken from the filtration chamber of the baghouse dust collectors. The first sample (S1) is untreated calcium phosphate dust, the second (S2) is the calcium phosphate dust from the outside of filter media while the third one (S3) is the calcium phosphate dust from the inside of filter media which causes clogging depth. In this paper, the rheology and the small-angle X-ray scattering (SAXS) of the three samples were investigated to elucidate the changes in terms of local structure, the viscosity, and the shear stress parameters. The rheological behavior of the dust samples was investigated for a solid mass concentration ranging from 50 to 60%, the three samples (S1) (S2) and (S3) had a solid mass concentration of C1=60%, C2=55% and C3=50% and a shear rate in the range from 1 to 1000 s
. The results indicated that during the filtration process, the pseudo-plastic behavior of the dust phosphate changed to that of Bingham. Comparing the results of the sample’s viscosity, we found that the viscosity decreased during the process filtration. The SAXS results suggested that the dust phosphate samples possess a fractal surface structure of enormous dust particles with a rough surface interface. This new study highlights the rheological behavior of grain phosphates that could be extrapolated to other mining powder as grains material or in solution. It is important to understand the rheological characteristics of materials, their flow, and the subsequent deformation of matter as a result of the flow.
The article examines the medicalization of pregnancy and childbirth and the tendency to humanize or demedicalize childbirth. The concept of childbirth dramatically changed in Western countries over ...the last century. Pregnancy and childbirth were still considered to be a natural phenomenon at the beginning of the 20th century. In the second half of the 20th century, which coincides with more intense development of gynaecology and obstetrics and the related technology, pregnancy and childbirth became the subject of the jurisdiction of medicine. Medicalization in Peter Conrad's terms is a process by which non-medical problems become defined as medical, which is also related to the implementation of medical interventions. A descriptive research method was used to perform a literature review related to the medicalization of pregnancy and childbirth. In addition to a general overview of the theme, the review focused on the Slovenian context. Discussions about the medicalization of pregnancy and childbirth and natural childbirth create ambivalence, since technological advances also help to save lives. The feminist critique sees the medicalization of pregnancy and childbirth in the function of control over women's bodies and reproduction. The process of humanization therefore focuses on woman and her ability to make independent decisions related to pregnancy and childbirth. Through the literature review, it is indicated that there is a need for further empirical research to explain more clearly the interweaving of these two perspectives, especially in Slovenia, where such studies are extremely limited. Adapted from the source document.
The interaction of proteins bound at distant sites on a nucleic acid chain plays an important role in many molecular biological processes. Contact between the proteins is established by looping of ...the intervening polymer, which can comprise either double- or single-stranded DNA or RNA, or interphase or metaphase chromatin. The effectiveness of this process, as well as the optimal separation distance, is highly dependent on the flexibility and conformation of the linker. This article reviews how the probability of looping-mediated interactions is calculated for different nucleic acid polymers. In addition, the application of the equations to the analysis of experimental data is illustrated.
This article describes how the probability of looping-mediated interactions is calculated for different nucleic acid polymers such as double- or single-stranded DNA or RNA, or interphase or metaphase chromatin.
Explanation of the patterns in Mie theory Berg, M.J.; Sorensen, C.M.; Chakrabarti, A.
Journal of quantitative spectroscopy & radiative transfer,
03/2010, Letnik:
111, Številka:
5
Journal Article
Recenzirano
The far-field scattered light intensity, or the related phase function, for a spherical particle is known to display an overall power-law structure when formulated in terms of the scattering wave ...vector. Empirically determined patterns in the intensity relating to the particle size and refractive index are known. The cause of the patterns, however, has not been satisfactorily explained. This work applies an exact microphysical model to explain most of the patterns, and specifically, to reveal the physical cause of crossovers from one power-law to another. A unique aspect of this microphysical approach is phasor analysis, which provides a visually based way to examine the angle-dependent wavelet superposition involved in the model. A simple color coding scheme connects the phasors to the interior of the particle, and it is this connection that reveals the meaning of the crossovers.
The objective of the study was to determine the course and outcomes of pregnancy and childbirth in adolescents compared to women aged 20-24 years in Slovenia.
In the retrospective study, the course ...of pregnancy and labour and the perinatal outcome of newborns in primiparous adolescents aged ≤19 years (study group) have been compared to the control group of primiparous women aged 20-24 years. The study group was further divided into a study subgroup of adolescents aged ≤17 years. Data were retrieved from the National Perinatal Information System in Slovenia for the period 2008-2012. Altogether, 13,663 women and their newborns were included.
Adolescent pregnancy was associated with increased rates of unknown estimated date of delivery, preterm labour, low birth weight newborns, small for gestational age newborns and low gestational weight gain. Spontaneous labour was more common in adolescents, while emergency and elective Caesarean sections were less common than in women aged 20-24 years. In addition, pregnancy in adolescents aged ≤17 years was associated with increased rate of maternal anaemia and labour without complications. Higher rates of smoking, lower rates of parenting school attendance, lower rates of pregnancy check-ups and screening tests in pregnancy such as nuchal translucency in adolescents were found.
The results of the study show that adolescent pregnancy is related to higher health risks for pregnant adolescents and their newborns. In addition, adolescents are subject to poorer prenatal care comparing to older women.
Uvod: Terapija surfaktantima postala je standard njege nedonoščadi sa sindromom respiratornog distresa (RDS) i sve se više koristi u terminske novorođenčadi s drugim patološkim stanjima. Primjena ...surfaktanta jedno je od najvećih postignuća u neonatalnoj skrbi koje je pridonijelo drastičnom smanjenju mortaliteta takve djece.
Cilj: Utvrditi razloge i učestalost primjene surfaktanta u neonatalnoj dobi te ispitati učestalost patoloških stanja prema gestacijskoj dobi.
Metode: Provedena je presječna epidemiološka studija. Istraživanje je provedeno u razdoblju od 1. siječnja 2017. do 31. prosinca 2019. godine. Studija je obuhvatila 73 neonatusa koji su liječeni sa surfaktantom na Odjelu za intenzivno liječenje na Klinici za dječje bolesti Sveučilišne kliničke bolnice (SKB) Mostar.
Rezultati: Od 73 novorođenčadi 52,1 % je liječeno surfaktantom zbog respiratornog distres sindroma (RDS-a), a 47,9 % razloga za davanje surfaktanta su druga patološka stanja u neonatologiji. 79,5 % ispitanika liječenih surfaktantom uz osnovno patološko stanje imali su 1 ili više pridruženih patoloških stanja. 78,1 % ispitanika je primilo 2 ili više doza surfaktanta ponovljenih prvi ili neki drugi dan liječenja.
Zaključak: Približno je podjednak broj djece koja su dobila surfaktant zbog RDS-a i drugih patoloških stanja. To dovodi do zaključka da je surfaktant značajno poboljšao liječenje i drugih patoloških stanja u neonatologiji.
To examine the effects of various maternal and neonatal perinatal factors on the child's body mass index (BMI) and physical fitness at school-age.
Data from two registries, the SLOfit database (a ...national surveillance system of children's motor and physical development) and Slovenian National Perinatal Information System (NPIS) were analysed. Perinatal data for 2,929 children born in 2008 were linked to results of SLOfit testing of these children in 2016. Linear regression analysis was used to assess the potential relationship between several perinatal factors (very preterm birth, birth mass, maternal age, hypertensive disorders of pregnancy, gestational diabetes, parity, plurality, maternal pre-pregnancy BMI, mode of delivery, presentation, Apgar score at 5 minutes, and admission to a neonatal intensive care unit (NICU)) and child's BMI or child's physical fitness index (PFI) at the age of eight years. We also included child's school grade and maternal educational level in the analysis. A p value <0.05 was considered statistically significant.
Children born to mothers with lower pre-pregnancy BMI and higher education had lower BMI and higher PFI (p<0.001) at school-age. Physical fitness was also inversely associated with nulliparity (p<0.001) and NICU admission (p=0.020).
Among all perinatal factors studied, higher maternal education and lower pre-pregnancy BMI seem to be the most significant determinants of child's BMI and physical fitness at school-age.
Multi-scale and fractal morphologies are ubiquitous in experiments. Accurate statements about sizes of domains and interfaces, roughness exponents, fractal dimensions, etc. can be obtained from the ...correlation function
C
(
r
)
and the structure factor
S
(
k
)
. Smooth morphologies are characterized by the Porod law. The
signature
of fractal domains and interfaces is a
power-law decay
of
C
(
r
)
and
S
(
k
)
with non-integer exponents. As typical experimental morphologies are smooth on some length scales and fractal on others, the structure factor is characterized by
cross-overs
from one form to another. We illustrate this with two examples: (i) ground state morphologies in dilute anti-ferromagnets; and (ii) droplet-in-droplet morphologies of double-phase-separating mixtures. The identification of fractal morphologies in these systems yields novel insights on the underlying micro-scale phenomena.
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