Blackbody Research Articles

Determination of the temperature of an object irradiated by microwaves using spectral pyrometry

Recently, due to increasing environmental requirements, microwave carbonization method has been widely investigated for the production of activated carbon from biomass waste. Microwave carbonization is a more energy efficient and environmentally friendly method compared to traditional carbonization in thermal furnaces, but to date there are still a number of questions about the reproducibility and temperature stability of this process. During microwave irradiation, the temperature of biomass samples changes continuously and complex physical and chemical processes occur in them. For deeper study of these processes and determination of optimal modes of microwave treatment it is necessary to know the temperature dynamics of biomass samples. For this purpose, the method of spectral pyrometry based on the allocation of sections of the spectra of thermal radiation of samples coinciding with the Planck spectrum was used. In the specified spectral sections these samples are gray emitters. The method is effective for an unknown emission coefficient, continuously varying with changes in the microstructure, chemical composition and phase state of the sample. The sample irradiated by microwaves was a sample of orthophosphoric acid-treated cotton down weighing 1 g. The microwave source was a magnetron-type generator with a maximum output power of 600 W and an operating frequency of 2450 MHz. Thermal spectra of the irradiated sample were recorded by small-size spectrometers of visible (350–760 nm) and near-infrared (650–1050 nm) ranges. The time of irradiation of samples by microwaves was varied in the range of 60–180 s. To process the obtained spectra, the program “Spectral Pyrometry” was used, which reads the recorded spectrum, processes it, plots it in the necessary coordinates and calculates the temperature. Analysis of the obtained results revealed different types of thermal radiation spectra of the irradiated sample - spectra similar to spectra of a completely black body, spectra with different temperature zones of the sample, spectra with atomic lines and molecular bands. The results obtained are useful for the study of microwave influence on various objects, research of processes occurring during carbonization of biomass, as well as for the development of more effective modes of production of activated carbons by microwave method.

Variegated racism: exploring experiences of anti-Black racism and their progression in medical education.

Addressing anti-Black racism in medical education in Canada has become increasingly urgent as more Black learners enter medical institutions and bring attention to the racist harms they face. We sought to gather evidence of experiences of racism among Black medical learners and to explore the contexts within which racism is experienced by learners. Drawing on critical race and structural violence theories, we conducted interviews with Black medical faculty, students, residents, and staff at the University of Saskatchewan College of Medicine between May and July 2022. We thematically analyzed interviews using instrumental case study methodology. Thematic analyses from 13 interviews revealed 5 central themes describing experiences of racism and the compounding nature of racist exposures as learners progressed in medicine. Medical learners experienced racism through uncomfortable encounters and microaggressions. Blatant acts of racism were instances where patients and superiors harmed students in various ways, including through use of the N-word by a superior in 1 instance. Learners also experienced curricular racism through the absence of the Black body in the curriculum and the undue pathologizing of Blackness. Medical hierarchies reinforced anti-Black racism by undermining accountability and protecting powerful perpetrators. Finally, Black women medical learners identified intersecting oppressions and misogynoir that compounded their experience of racism. We propose that experiences of racism may worsen as learners progress in medicine in part because of increases in the sources of and exposure to racism. Anti-Black racism in medical education in Canada is experienced subtly through microaggressions or blatantly from different sources including medical faculty. As Black learners progress in medicine, anti-Black racism may become worse because of the compounding effects of exposures to a wider range of sources of racist behaviour.

In Vivo Imaging of Rabbit Follicles through Combining Ultrasound Bio-Microscopy and Intravital Window.

Continuous ovarian imaging has been proven to be a method for monitoring the development of follicles in vivo. The aim of this study was to evaluate the efficacy of combining ultrasound bio-microscopy (UBM) with an intravital window for follicle imaging in rabbits and to monitor the ovarian dynamic processes. New Zealand White female rabbits (n = 10) received ovarian translocation to a subcutaneous position. The ovarian tissue was sutured onto the abdominal muscles and covered with an intravital window for the continuous monitoring of the follicles using UBM. Results show that physiological changes (red blood cell and white blood cell counts, feed intake, and body weight change) in rabbits induced by surgery returned to normal physiological levels in one week. Furthermore, UBM could provide high-resolution imaging of follicles through the intravital window. Daily monitoring of ovarian dynamic processes for 6 days displayed variabilities in follicle counts and size. Collectively, these results provide a relatively new method to monitor ovarian dynamic processes and to understand the reproductive physiology of female rabbits.

A new novel recognition and positioning system of black light-absorbing volute for automation depalletizing development

Abstract In the application of vision measurement, the black light-absorbing object is difficult to reflect the structured light from infrared emitter of the RGB-D camera. Therefore, an image recognition algorithm based on reference environment information is proposed to acquire the spatial positioning information of black volutes in the depalletizing system. The hardware system of the depalletizing system is mainly constructed of an upper computer, a six-axis industrial robot, an RGB-D camera and an end adsorption device. Firstly, the horizontal position information of each volute placed on the cardboard is obtained by the depth differences between the cardboard and the volute. Then, the depth information of the volute is obtained by the upper cardboard depth through collecting the position of the end vacuum suction cup triggered by feedback signal from vacuum generator. Secondly, a regional planar hand-eye calibration method is developed to improve the calibration accuracy in two-dimensional coordinates. The regional calibration method divides the robot working area into four regions: upper left, lower left, upper right, and lower right. The transformation matrix of each region is calculated separately. Finally, the depalletizing experiment is conducted on the three types of volutes. It is concluded that the average positioning error of the grasping center point of each volute obtained by our method is 3.795 mm, and its standard deviation is 1.769 mm. The average value of regional planar hand-eye calibration error is 4.044 mm, and its standard deviation is 1.501 mm. Under a stack of materials with dimensions of 1350 mm × 1350 mm × 1500 mm, the maximum error is controlled within 15 mm. Additionally, when combined with the end feedback compensation mechanism, the success rate for grasping all three volutes reaches 100%.

Representing science: diversity on the President’s Council of Advisors on Science and Technology

Abstract Federal advisory committees related to science and technology are important mechanisms for connecting policy-makers with independent experts and the broader public. The balance of represented expertise and viewpoints shapes a committee’s intended advisory role, consensus building processes, and the quality and impact of its policy recommendations. This paper presents the first historical analysis of the President’s Council of Advisors on Science and Technology (PCAST) and examines its changing balance of social and professional perspectives from 1990 to 2023. We demonstrate that PCAST’s balance has shifted to be more inclusive of different social groups and professional backgrounds over time, particularly under President Biden. We conclude with recommendations for future White House science policy advisory bodies to ensure they are adequately representative of the diversity of perspectives in the US research enterprise and the overall US population.

Supramassive dark objects with neutron star origin

Supramassive dark objects with neutron star origin

Microlensing signatures of extended dark objects using machine learning

This paper presents a machine learning-based method for the detection of the unique gravitational microlensing signatures of extended dark objects, such as boson stars, axion miniclusters and subhalos. We adapt MicroLIA, a machine learning-based package tailored to handle the challenges posed by low-cadence data in microlensing surveys. Using realistic observational time stamps, our models are trained on simulated light curves to distinguish between microlensing by pointlike and extended lenses, as well as from other object classes which give a variable magnitude. We focus on boson stars and Navarro-Frenk-White (NFW) subhalos and show that the former, which are examples of objects with a relatively flat mass distribution, can be confidently identified for 0.8≲r/rE≲3. Intriguingly, we also find that more sharply peaked structures, such as NFW subhalos, can be distinctly recognized from point lenses under regular observation cadence. Our findings significantly advance the potential of microlensing data in uncovering the elusive nature of extended dark objects. The code and dataset used are also provided. Published by the American Physical Society 2024

Hematologic parameters as predictors of overall survival in metastatic solid tumor and aggressive lymphoma.

e23053 Background: Aggressive cancer is associated with an increased rate of thrombosis. In addition to body mass index (BMI), the Khorana score has identified several hematologic parameters associated with an increased risk of thrombosis. In this study, we assessed the relationship of these parameters with overall survival. Methods: Using data from our tumor registry, we selected patients with aggressive lymphomas (AL), glioblastoma multiforme (GBM), metastatic prostate (MP), metastatic lung (ML), and metastatic colorectal (MCRC) cancer from 2018 to 2023. Laboratory data were extracted from our electronic medical record, with a timeframe of 90 days before and 30 days after first contact, but prior to initiating treatment. We analyzed the relationship of hemoglobin (Hgb), white blood cell (WBC) count, platelet (Plt) count, and body mass index (BMI), with overall survival (OS). Each cancer type was analyzed as a separate group and multivariable analysis was controlled by sex and age at diagnosis. Dichotomizing the variables from categories of the Khorana score, we evaluated the relationship of such variables and OS using Kaplan-Meier Analysis and Cox Proportional Hazards Models. Patients were censored at two years of follow-up. Data analysis was done using R (version 4.3). Results: Of 2,362 patients, 55% were male, and median age was 63 years. (Cancer types: 622 ML, 604 AL, 453 GBM, 281 MCRC, 203 MP, and 199 MB). An initial, pre-treatment Hgb < 10 g/dL was associated with a shorter OS in patients with ML, MCRC, MP, and AL patients. Plt ≥350 x 109/L was associated with a shorter OS in ML and MCRC patients. WBC > 11 x 109/L was associated with a shorter OS in ML, AL, and MCRC, and a BMI ≥35 was associated with a shorter OS only in GBM patients (Table). Conclusions: While not in all cancer types, the hematologic parameters of the Khorana score that predict thrombosis correlate with a reduced overall survival. This effect was significant for different parameters in different cancers. The increased hazard ratio is beyond that which would be expected from thrombosis-related mortality. Our study is limited to data from our single institution and the retrospective nature of the study. [Table: see text]

Racial Biases in AIs and Gemini's Inability to Write Narratives About Black People

This article addresses the racism that emerges in artificial intelligence based on an experiment carried out in Gemini, Google's text-generative tool that uses natural language. In an attempt to observe possible racial biases in the chatbot's responses, commands reproduced for the binary matrices man/woman and white/black were submitted in order to compare the responses, but Gemini, despite having text production as its primary function, was unable to generate narratives that involved black people. This empirical experimentation was analyzed according to a bibliographical review of authors who deal with racial themes, mainly considering the view of Denise Ferreira da Silva in relation to the idea of a transparent subjectivity, the temporal displacement of the black body discussed by Bhabha and the overlap between technology and race brought by Noble and Faustino and Lippold. This erasure of minoritized racial groups is not restricted to the tool or the algorithmic means, but is a symptom of other exclusionary practices observed in society.

Upper bound on thermal gravitational wave backgrounds from hidden sectors

Hot viscous plasmas unavoidably emit a gravitational wave background, similar to electromagnetic black body radiation.We study the contribution from hidden particles to the diffuse background emitted by the primordial plasma in the early universe.While this contribution can easily dominate over that from Standard Model particles, we find that both are capped by a generic upper bound that makes them difficult to detect with interferometers in the foreseeable future.We illustrate our results for axion-like particles and heavy neutral leptons.Finally, our results suggest that previous works overestimated the gravitational wave background from particle decays out of thermal equilibrium.

Detection of a cyclotron line in the Be X-ray pulsar IGR J06074+2205

Context. IGR J0607.4+2205 is a transient Be X-ray binary discovered two decades ago. IGR J0607.4+2205 underwent an outburst in 2023 during which it was observed twice with NuSTAR. Aims. The main goal of this work is to model the broadband X-ray spectrum of IGR J0607.4+2205 during the outburst and to study the variations of the spectral and timing features at different intensities. Methods. We extracted the light curve and spectrum of the source from the two NuSTAR observations carried out during the recent outburst in the energy range of 3−78 keV. We used the epoch folding technique to find pulsation from the source and to study the changes in emission characteristics from the source with energy across an order of magnitude variation in source luminosity. Results. IGR J0607.4+2205 shows pulsations with a period of ∼347.6 s during both the observations, with a pulse fraction of ≥50%. The broadband spectrum of the source was modelled using a power-law continuum with a high-energy cutoff. During the first observation, a cyclotron absorption line at ∼51 keV was also present in the source with an optical depth of ∼1.3. However, no cyclotron line feature was detected in the second observation when the source was an order of magnitude fainter. Additionally, soft excess was detected in the second observation, which was modelled with a black body component emerging from close to the neutron star (NS). Conclusions. We report the first ever detection of a cyclotron line in the broadband spectrum of IGR J0607.4+2205 centred at 51 ± 1 keV. The magnetic field strength of the NS is estimated to be ∼4 × 1012 G from the centroid energy of the absorption line. A significant change is observed in the pulse profile with luminosity during the decay of the outburst, indicating an associated change in the beaming pattern.

Estimation of the Ionospheric D‐Region Ionization Caused by X‐Class Solar Flares Based on VLF Observations

AbstractIn this paper, we study the ionization‐recombination processes in the lower ionosphere during solar flares of various classes in June 2014 and September 2017. For the first time, ionization and recombination rates of the ionospheric D‐region were estimated using the experimental data on variations in the amplitude and phase characteristics of very low frequencies (VLF) signals and two‐channel data from the GOES satellite (0.05–0.4 nm and 0.1–0.8 nm). The empirical two‐parameter Wait‐Ferguson model was used to calculate temporal changes in the electron concentration Ne during solar flares of different classes. GOES satellite data and black body model were used to estimate the X‐ray fluxes in the wavelength spectral range λ ≤ 0.3 nm. Joint analysis of the temporal evolution of the Ne vertical profile in the lower ionosphere and X‐ray fluxes in different wavelength ranges was carried out. As a result, the values of the ionization and recombination rate coefficients were obtained, and the spectral ranges of radiation that have the greatest impact on Ne at given heights were determined. Calculated ionization and recombination rate coefficients and ranges were successfully verified using VLF data during different solar flares. The results obtained in this work can be used in future studies for a more accurate assessment of the response of lower ionosphere to solar flares of various classes.

Decolonial Embodiments: Materiality, Disability, and Black Being in Djaimilia Pereira de Almeida’s Luanda, Lisboa, Paraíso

Grounded in, and in dialogue with, Djaimilia Pereira de Almeida’s Luanda, Lisboa, Paraíso of 2018, this paper interrogates a particular time and place of coloniality and racial capital’s reproduction of Black fungibility in late twentieth-century Portugal, after formal decolonization in Africa and in the wake of Black migratory waves from the post/neo-colony (Angola in this case) to the former metropolis. Almeida’s novel provides a literary intervention in grappling with the economic and institutional reinvention of anti-Blackness in Europe after settler colonialism, while also imagining and inscribing modes of Black being within and beyond the materialities of white supremacy. Towards this end and against the racial, gendered, and ableist logics of capital, the Black body in Almeida’s novel becomes a site through which the relationships between humans and matter as well as mind and body are decolonially revised.

Migration, Human Trafficking, Sexploitation and Trauma in Amma Darko’s Beyond The Horizon

Human trafficking and sexploitation have become prevalent migration configurations in Africa that often plunges the victims into harrowing mental, emotional, and physical trauma. This paper aims at portraying African female immigrants’ experiences in Amma Darko’s Beyond the Horizon projecting the female migrant characters as victims of human trafficking, sexual abuse, and economic exploitation in the hands of their selfish and egoistic husbands. Given the complexities of the lives of African women who immigrate to Europe and get caught in a spider’s web of prostitution and pornography, the fictionalized German universe in the text reveals that Europe is not the “Eldorado” where milk and honey flows in abundance as perceived by most Africans. The paper’s analysis employs a feminist analytical framework to examine the objectification and commodification of the black female body. It submits that, despite their traumatic experiences, these African immigrant women assert their sexuality by challenging the status quo thereby obtaining for themselves an emancipated female agency that allows them to take control of their own bodies as well as their financial gains.

How horror films constructs Blackness: examples of White supremacist media’s enforcement of necropolitics in genre film

ABSTRACT Recently, there has been in uptick in Black horror in the horror genre, such as Jordan Peele’s Get Out, US, or HBO’s Lovecraft Country. Despite the recent growth of Black horror, many horror films continue depend on film technologies that contribute to oppression. The necropolitics of the horror genre is apparent as most horror films fail their Black characterss—often brutalizing or silencing them and using the screen to reify a life of suffering and death. I argue that horror can serve as a visual representation of white supremacist values and creates models of Blackness that perpetuate stereotypes and necropolitical control. The white monster, or the monstrous white, cannot allow the Black body to continue or, at least, not in an untouched state. Thus, recreating controlling images that contribute to viewers’ understanding and perception of the world around them. Using various staples of the horror genre, from the last 30 years, I will show how certain horror technologies function to oppress Black sexuality, survival, and hope by reinscribing suffering in an onscreen, affective, mimesis that is so widespread it has become almost inescapable within the genre.

A Sociocultural Exploration of the Impact Body Image Has on Black College-Aged Women’s Mental Health

This study aimed to explore the relationship between Black cultural identity body image and mental well-being among Black Americans and Black immigrant women who attend predominately white universities (PWIs). As part of the Multi-Site University Study of Identity and Culture (MUSIC) survey, participants completed the Brief Inventory of Body Image, which included questions such as “I’m proud of my body,” “I often feel ugly,” ‘I have a good figure,” “I’m ashamed of my body,” and “I am anxious about the way I look.” The results showed that there were several similarities between the subgroups in the correlations between body image and mental health indices, such as social anxiety, depression, psychological well-being, and self-esteem. Both Black American and Black immigrant college-aged women had a positive association between body image and indicators of Black women’s sense of self, like self-esteem and psychological well-being. They also had a negative association between body image and mental health, such as social anxiety and depression. However, there was one key difference in that Black American women had a stronger association between their sense of self and self-esteem and psychological well-being compared to Black immigrant women. These findings support other studies that suggest Black women tend to have a stronger positive body satisfaction relative to their overall mental well-being. The study has important implications for the understanding of Black women, ethnic identity, body image, and mental health, which are discussed in the paper.

Characterization and Validation of ECOSTRESS Sea Surface Temperature Measurements at 70 m Spatial Scale

The ECOSTRESS push-whisk thermal radiometer on the International Space Station provides the highest spatial resolution temperature retrievals over the ocean that are currently available. It is a precursor to the future TRISHNA (CNES/ISRO), SBG (NASA), and LSTM (ESA) 50 to 70 m scale missions. Radiance transfer simulations and triple collocations with in situ ocean observations and NOAA L2P geostationary satellite ocean temperature retrievals were used to characterize brightness temperature biases and their sources in ECOSTRESS Collection 1 (software Build 6) data for the period 12 January 2019 to 31 October 2022. Radiometric noise, non-uniformities in the focal plane array, and black body temperature dynamics were characterized in ocean scenes using L1A raw instrument data, L1B calibrated radiances, and L2 skin temperatures. The mean brightness temperature biases were −1.74, −1.45, and −1.77 K relative to radiance transfer simulations in the 8.78, 10.49, and 12.09 µm wavelength bands, respectively, and skin temperatures had a −1.07 K bias relative to in situ observations. Cross-track noise levels range from 60 to 600 mK and vary systematically along the focal plane array and as a function of wavelength band and scene temperature. Overall, radiometric uncertainty is most strongly influenced by cross-track noise levels and focal plane non-uniformity. Production of an ECOSTRESS sea surface temperature product that meets the requirements of the SST community will require calibration methods that reduce the biases, noise levels, and focal plane non-uniformities.

Humanity Defined, Hypocrisy Defied: Sacralizing the Black Freedom Struggle, 1930–60

The white ecclesia in the United States either opposed or equivocated on the matter of the humanity of African Americans. The 1939 unification of majority white Methodist bodies, for example, structurally segregated black members into a separate Central Jurisdiction. This action mimicked practices in the broader body politic that crystallized in American society both de jure and de facto systems of second-class citizenship for African Americans. This hypocrisy mobilized adherents of Gandhian non-violence and elicited from them tenets and tactics which energized moral methodologies that defeated a church and civic collusion that perpetrated black subordination. Interracial alliances derived from the ecclesia and parachurch organizations articulated non-violence as a moral precept that sacralized a grassroots civil rights movement. This initiative morally discredited the racial hypocrisy aimed at America's formerly enslaved and segregated population.

Construction of Urban Black and Odorous Water Remote Sensing Recognition Model Based on Feature Band

In recent years, with the rapid development of urban and rural areas in China, the discharge of industrial wastewater and household sewage has increased greatly, which has been directly discharged into pits and rivers, causing serious pollution of these bodies of water.In this study, the sampling points were first divided into black and odorous water bodies and general water bodies. Combined with remote sensing images, the best threshold value of the most effective feature bands in the classification of the study area was explored through the threshold method, and the accuracy performance of different feature bands in the classification process was comprehensively evaluated.In the algorithm of black and odorous water body identification based on characteristic bands, the thresholds of the single-band method, the difference method of black and odorous water body and the slope index of black and odorous water body in the experimental area of Nanning are 0.0186, 0.004 and 0.007 respectively. These three algorithms are used as thresholds to distinguish black and odorous water bodies from ordinary water bodies. The normalized black and odorous water index model determines that the range of black and odorous water is 0.007-0.137.

About Cosmic Microwave Background Radiation (CMBR)

Because the CMBR follows the PLANCK's radiation law more or less exactly, it should, because of the indistinguishability of individual photons, apply to a whatever black emitter. Therefrom arises the guess, that the existence of an upper cut- off frequency of the vacuum could be the cause for the decrease in the upper frequency range. Since the lower-frequent share of the curve correlates with the frequency response of an oscillating circuit with the Qfactor ½, it is examined, whether it succeeds to approximate the Planck curve by multi-plication of the initial curve with the dynamic, time- dependent frequency response of the above-mentioned model. Reason of the time-dependence is the expansion of the universe. This work is based on a model published in [1]. It is shown, that the PLANCK graph can be approximated by application of the cumulative frequency response given by the model, upon the spectrum of an oscillatory circuit with the Q-factor ½. Furthermore, the progression of frequency, energy and entropy is analysed. The results point out, that origin and progression of the CMBR have elapsed in a totally different manner than generally assumed. Because photons behaved like neutrinos immediately after BB they did not interact with other matter then. Thus, we can exactly calculate back to 8.08·10–106s instead of 379,000 years after BB. Section 6 has been reworked.