Application of a CdTe Detector for Measurements of Mammographic X-ray Spectra

This work aims to characterize mammographic x-ray beams incident and transmitted by breast phantoms (from 0 to 45 mm) composed from known proportion of glandular and adipose tissue-equivalent materials. This study was performed for mammographic x-ray beams generated by a mammography equipment using different target/filter combinations (Mo/Mo, Mo/Rh and W/Rh). It was studied the modification of spectra shape of the beams transmitted through different thicknesses of these materials. It was also evaluated the penetrability of these transmitted beams by its correlations to the HVL, which were experimentally estimated and derived from the x-ray spectra measured using a spectrometry system with a CdTe detector. The x-ray spectra transmitted by the phantom with higher density presented lower intensity than those transmitted by those with lower density, as expected. The differences between the HVL values derived from the spectra and those estimated using air kerma measurements are lesser than 6% for about 88% of the spectra measured in this work. The expected spectra variations with phantom thickness, revealed by the measured transmitted x-ray spectra, were also confirmed by HVL measurements and agree with the estimated attenuation curves.The motivation of the study was related to the robustness of the spectra as a descriptor of radiation beams and the possibility of using these transmitted spectra for dose assessment related to mammographic procedures. We can conclude that developed method is able to characterize mammographic x-ray beams making it possible the use of this kind of data for dose assessment in mammography

Chromium Adsorption on Banana Rachis Adsorbent from Tannery Wastewater: Optimization, Isotherm, Kinetics and Desorption Studies

This study investigates the banana rachis adsorbent for adsorption characterization, removal, and recovery of the chromium ion from the chrome tanning wastewater. The batch analysis was conducted to find out an adsorbent dose, contact time, relative pH of the aqueous solution, and initial and final chromium value in the filtrate. The equipped adsorbent was studied by the Fourier transform infrared spectroscopy (FT-IR) analysis to reveal the associated functional groups during adsorption. Batch adsorption examination reveals the optimum conditions of 3 g adsorbent input for 75 mL wastewater at 15 min contact time. The adsorption mechanism showed chromium removal 99.64% with the obtained reduction of biochemical oxygen demand (BOD), chemical oxygen demand (COD), and chloride (Cl-) 96.65%, 93.18%, and 59.62%, respectively. The adopted method followed the pseudo-second-order kinetics and Freundlich isotherm for physical adsorption. Primary desorption studies exhibit a scope for the reuse of chromium from the adsorbed adsorbent. Moreover, in comparison with other studies, the study discloses that banana rachis might be utilized as a feasible adsorbent to be adopted in industrial wastewater treatment, especially chrome tanning wastewater in the tannery

Sorption comparison of trivalent chromium on various Ficus carica charcoal from tannery wastewater

Content: In this study, equipped charcoal of Ficus carica without impregnation, impregnated with potassium hydroxide (KOH), zinc chloride (ZnCl2) and phosphoric acid (H3PO4) was used for sorption comparison of trivalent chromium from tannery wastewater. The equipped charcoal is characterized before and after used by Fourier transforms infrared spectroscopy (FT-IR). The quantitative elemental analysis is performed of the charcoal using PGT Energy dispersive X-ray spectrometry (EDX). The trivalent chromium sorption efficacy of charcoal was examined investigating charcoal dose, contact time, and relative pH parameters. Batch sorption test revealed that Ficus carica charcoal without impregnation had the maximum sorption capacity of trivalent chromium as depicted Fig. 1a. At the same conditions, trivalent chromium sorption on the Ficus carica charcoal without impregnation, impregnated with potassium hydroxide, zinc chloride and phosphoric acid was 98.9%, 98.8%, 8.9 and 2.5%, respectively. It is noticeable that without impregnation charcoal has a higher sorption capacity. Conversely, impregnation with chemical required cost involvement, time-consuming, long process time, and safe. Fig.1b depicts a shift in the peak intensity which indicated the change of frequency in the functional groups of the charcoal due to chromium adsorption. It indicates various responsible functional groups for the removal of trivalent chromium through Ficus carica charcoal. The trivalent chromium removal efficiency with the Ficus carica charcoal without impregnation was achieved 98.9%. The study could be helpful to design the sorption of trivalent chromium from the tannery wastewater in-house prior to discharge. Take-Away: 1. Without impregnation, Ficus carica charcoal has a better trivalent chromium sorption capacity 2. Trivalent chromium sorption capacity was 98.9

Religiosity and teen birth rate in the United States

<p>Abstract</p> <p>Background</p> <p>The children of teen mothers have been reported to have higher rates of several unfavorable mental health outcomes. Past research suggests several possible mechanisms for an association between religiosity and teen birth rate in communities.</p> <p>Methods</p> <p>The present study compiled publicly accessible data on birth rates, conservative religious beliefs, income, and abortion rates in the U.S., aggregated at the state level. Data on teen birth rates and abortion originated from the Center for Disease Control; on income, from the U.S. Bureau of the Census, and on religious beliefs, from the U.S. Religious Landscape Survey carried out by the Pew Forum on Religion and Public Life. We computed correlations and partial correlations.</p> <p>Results</p> <p>Increased religiosity in residents of states in the U.S. strongly predicted a higher teen birth rate, with r = 0.73 (p < 0.0005). Religiosity correlated negatively with median household income, with r = -0.66, and income correlated negatively with teen birth rate, with r = -0.63. But the correlation between religiosity and teen birth rate remained highly significant when income was controlled for via partial correlation: the partial correlation between religiosity and teen birth rate, controlling for income, was 0.53 (p < 0.0005). Abortion rate correlated negatively with religiosity, with r = -0.45, p = 0.002. However, the partial correlation between teen birth rate and religiosity remained high and significant when controlling for abortion rate (partial correlation = 0.68, p < 0.0005) and when controlling for both abortion rate and income (partial correlation = 0.54, p = 0.001).</p> <p>Conclusion</p> <p>With data aggregated at the state level, conservative religious beliefs strongly predict U.S. teen birth rates, in a relationship that does not appear to be the result of confounding by income or abortion rates. One possible explanation for this relationship is that teens in more religious communities may be less likely to use contraception.</p

AIDing Contraception: HIV and Recent Trends in Abortion Rates

Since the onset of HIV/AIDS awareness in the early 1980s, much attention has centered around the substantial negative effects of the disease throughout the world. This paper provides evidence of a secondary effect the disease has had on sexual behavior in the United States. Using a difference-in-differences estimation framework and state level data, we show that the perceived threat of HIV resulted in a drop in unwanted pregnancies, as demonstrated by a lower incidence of abortions. Our results suggest that each additional reported case of HIV per 1,000 individuals resulted in 85.5 fewer abortions per 1,000 live births

New Century, Old Disparities: Gender and Ethnic Wage Gaps in Latin America

This paper surveys gender and ethnic wage gaps in 18 Latin American countries, decomposing differences using matching comparisons as a non-parametric alternative to the Blinder-Oaxaca (BO) decomposition. It is found that men earn 9-27 percent more than women, with high cross-country heterogeneity. The unexplained pay gap is higher among older, informal and self-employed workers and those in small firms. Ethnic wage differences are greater than gender differences, and educational attainment differentials play an important role in explaining the gap. Higher ethnic wage gaps are found among males, singleincome generators of households and full-time workers, and in rural areas. An important share of the ethnic wage gap is due to the scarcity of minorities in highpaid positions

Determination of the energy potential of biogas in selected farm household

Produkcja biogazu w Polsce corocznie zwiększa swój udział w wytwarzaniu energii odnawialnej kraju, a także stanowi doskonałą metodę zagospodarowania odpadów organicznych z rolnictwa oraz przemysłu rolno-spożywczego. Powstały w wyniku fermentacji metanowej biogaz jest wykorzystywany do produkcji energii elektrycznej jak i cieplnej. Celem pracy było wyznaczenie ilości wydzielanego biogazu, z dostępnej biomasy, uzyskanej w wyniku działalności rolniczej gospodarstwa, zlokalizowanego w miejscowości Kazimierza Wielka. Na podstawie otrzymanych wyników obliczono ilość energii możliwą do uzyskania z dostępnej biomasy w gospodarstwie rolnym. Wszystkie badania nad jakością i ilością wydzielonego biogazu zostały przeprowadzone w laboratorium biogazowni znajdującym się na Wydziale Inżynierii Produkcji i Energetyki Uniwersytetu Rolniczego w Krakowie. Badaniu zostały poddane następujące frakcje pochodzenia rolniczego: liście buraka cukrowego, korzeń buraka cukrowego, słoma z kukurydzy oraz kiszonka z kukurydzy. Na podstawie dostępnych materiałów oraz przeprowadzonych badań, dobrano generator tłokowy o mocy 350 kW a całkowita energia możliwa do wytworzenia wynosi ok. 2806 MWh. Ma podstawie przeprowadzonej analizy wynika, że badane gospodarstwo rolne może prowadzić działalność związaną z produkcją biogazu, która będzie stanowić dywersyfikacje jego dochodów.The production of biogas in Poland each year is increasing its share in renewable energy in the country, it is n excellent method of waste disposal as well. Biogas produced in the process of methane fermentation is used to produce electricity and heat. Determining the amount of biogas produced as a result of methane fermentation of available biomas generated from a selected farm household. This research disseratation was written on the basis of the available literature concerning the production of biogas and renewable energy sources the research methodology was based on the German standard DIN 38414. Using the available materials and research studies, a 350 kW piston generator was chosen; the total energy possible to be generated is approx 2806 MWh. As is clear from the foregoing, farm household under study can engage in the production of biogas,, which will provide additional income for farmers

Estimation of glandular dose in mammography based on artificial neural networks

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESThis work proposes using artificial neural networks (ANNs) for the regression of the dosimetric quantities employed in mammography. The data were generated by Monte Carlo (MC) simulations using a modified and validated version of the PENELOPE (v. 2014) +659117FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES2015/21873-82016/15366-9140155/2019-8001This work was supported by the Brazilian agencies Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, Project numbers 2015/21873-8 and 2016/15366-9), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPQ) project number 140155/201

Microrecycling solution for conversion of waste plastics into high quality products using available machinery

Plastic revolutionised the world, but meantime generates a substantial amount of waste plastics. However, plastics are generally non-biodegradable and hence remain in the environment for a very long time. Most plastics are not discarded properly, these wastes either end up in the landfills or left in the environment which can end up in water systems including oceans. Alternatively, plastics are burned to remove from premises or to recover energy. Today it is well established that if waste plastics are not deal properly, they can pose a great risk to both the people and the environment and at the same time a lot of valuable materials will be lost. However, only a small percentage of waste plastic is currently recycled due to the limitations of recycling and reprocessing technology, which requires massive infrastructure and normally is not economically feasible and environmentally sustainable. To overcome these challenges, several easy-to-operate and less cost incentive processes have been evaluated throughout this PhD project. This project first began by investigating the effect of reprocessing on polymer, which is important to develop efficient and effective recycling processes. At the next step a simple process that required fewer steps has been developed to utilise waste hard plastics as feedstock to produce new plastic products whilst retaining the original properties and colour of input waste plastics. Then, two novel processes have been demonstrated for another two types of problematic waste plastic (fishing net and flexible plastic packaging). In the final part of this research, three-dimensional (3D) printing, an advanced method of manufacturing, has been employed to transform waste plastics from toys into products. All produced plastics from the proposed methods showed good mechanical performances as virgin material. Life cycle assessment indicated that the processes could reduce greenhouse gas emission, fossil fuel depletion and ecotoxicity. Considering the conclusions of this project, different methods demonstrated in this thesis can manage and transform a wide range of waste plastics (from hard to soft) into high-quality plastics. They are not limited to the case studied waste plastics rather they have the potential to deal with other similar kinds of waste plastic. Overall, this research will create value for waste plastics, and in turn, speed up their collection and recycling

Study on the Direct Transformation of Milk Bottle and Wood into Wood&ndash;Plastic Composite through Injection Molding

Plastic has transformed the world; however, it generates a huge amount of waste plastics. It is well evident that, if urgent action is not undertaken on plastic pollution, it will pose threats to not only the environment, but also human life. Just simply discarding waste plastics will result in wasting a lot of valuable materials that could be recycled. Recently, the use of waste plastics has been considered for producing wood plastic composites (WPCs), which are superior to normal wood. Waste plastics are pelletized using an extruder and are then subjected to injection molding. In this study, investigations were carried out to determine the possibility of producing WPCs without the palletization of waste plastic to turn WPC production into a shorter, simple, and easy-to-achieve process. Here, a waste milk bottle, a familiar single-use plastic, was picked as a case study. Waste plastic granules and wood particles were mixed and directly injection molded to produce valuable WPCs. The water absorption of WPCs with 20% wood is 0.35%, and this increased to 0.37% when wood content was increased to 40%. The tensile strength at yield, elongation at break, and impact strength of WPCs with 20% wood content are 19.54 MPa, 5.21%, and 33.92 KJ/m2, respectively, whereas it was 17.23 MPa, 4.05%, and 26.61 KJ/m2 for the WPCs with 40% wood content. This process can be a potential solution for two problematic wastes at the same time