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Precise measurements of the dissipation and resonant frequency of a torsion pendulum reveal an anomaly in the inferred viscosity and normal density of liquid $$^3$$ He near the superfluid transition. We present an argument that the anomaly originates in the large viscosity and large viscosity change of the normal component in the torsion tube in the vicinity of the superfluid transition.

As a result of anthropogenic human activity and the continuous increase in the scale of water consumption, surface and groundwater, which are sources of freshwater, have been degraded. Most water sources have high iron content today. Contamination of groundwater with iron and other metals can occur due to the development of ore deposits and the operation of quarries. Existing technologies only partially solve this problem. Ions of heavy metals are toxic and dangerous for living organisms and for human beings. In this regard, it is important to develop effective methods of water treatment of various pollutants. Today, pollution of water bodies with iron ions has reached a critical level. This creates a problem for many regions not only in Ukraine, but also far beyond its borders. The problem is urgent and needs to be solved. When the pH value in water is less than 6.8–7.0 and the concentration of iron is high, for deep purification, it is advisable to use a combination of a number of methods with the introduction of reagents. Reagent method of deironing is implemented by treating the source water with a suspension of lime water Ca(OH)2. This approach allows one to deirone water effectively, but its implementation is accompanied by the formation of a large amount of sludge, which must be disposed of. An effective way to dispose of such precipitates is their use as a chemical additive in the production of cement, which was confirmed by our research.

The paper presents the results of studies of the effect of the concentration of binder components on the properties of cement alkaline stone. Formulations of clinker-free binders of alkaline activation with the level of filling the system of 20 and 40% have been developed, the properties of the cement paste of the binding binder "aspiration dust - mineral powder - liquid glass" have been studied, the dynamics of a set of strength indicators has been studied, both for bending and compressive forces. The received results allow to estimate uniqueness of properties of a binding binder "a mineral powder - Na2SiO3" and to create new materials on resource saving and energy saving technology. The results presented in this article were obtained within the framework of studies on the implementation of scientific project No. 05. 607.21.0320. "Development of technology for new building composites based on clinkerless cement of alkaline activation using substandard natural and secondary raw materials" supported by the Federal Target Program "Research and Development in Priority Areas of Development of the Scientific and Technological Complex of Russia for 2014-2020". The unique identifier for the agreement is RFMTFI60719X0320.

The object of research is organic additives of methyl hydroxyethyl cellulose of medium and high viscosity, namely, their nature of the effect on the physical and mechanical durability under the destructive influence of various sulfate-ionic media. The need to study the nature of the effect of this additive on resistance to an aggressive environment is also associated mainly with the expansion of the types of building mixtures to create competitive products without losing product quality and to improve the mechanical and rheological properties. In the course of the study, cellulose ethers of medium (17000–23000mPa∙s) and high (20,000–30,000mP s) viscosity were used. Additives were added to the cement in the amount of 0.25, 0.5 and 0.75wt.%. It was found that the introduction of cellulose ether into cement leads to an increase in the normal density of the dough and an extension of the setting time of solutions, in turn, affects the process of strength gain of the latter, in comparison with control samples without additives. With the introduction of the additive, the rate of water separation of the mixtures also significantly decreases, indicating the water-retention capacity of the additive. For the concentration of additives in the amount of 0.25wt.%. This decrease is 2 times less than for control samples. For a concentration of 0.5–0.75wt.% Water loss is reduced by 3 times compared to samples without additive. Significant changes also occur during the early strength gain of the samples with an increase in the additive concentration. The destructive effect of an aggressive sulfate medium was determined by the change in compressive strength. With prolonged exposure to an aggressive environment on control and test samples, it is noted that the introduction of this additive of organic origin negatively affects the strength characteristics of cement mixtures with cellulose ethers with an increase in the additive content. The above results indicate the advisability of using cellulose ethers of medium viscosity in dry building mixtures as such, which will provide the necessary storage time for the fluidity of the solution and sufficient strength of the final material.

The alkaline clinker-free binders formulations activation development based on fine powders of aluminosilicate nature will allow to obtain the effective building composites. The paper reveals the issues related to the theoretical foundations of the cement stone structure and strength formation based on the alkaline activator. The research results, in our opinion, are undoubtedly of practical importance for the construction industry, since the proposed recipes for clinker-free cements will replace the expensive and energy-consuming Portland cement, allowing to create strong and durable concrete and reinforced concrete structures. The results presented in this article have been obtained in the framework of research on the implementation of scientific project No. 05. 607.21.0320. “Development of technology for new building composites on clinker-free alkaline binders using substandard natural and secondary raw materials” which received support from the federal target program “Research and Development in Priority Directions for the Development of the Russian Science and Technology Complex for 2014-2020”. The unique identifier for the agreement is RFMTFI60719X0320.

The effect of a methyl hydroxyethyl cellulose additive on the technical and physical-mechanical properties of the cement matrix has been investigated. The study involved cellulose ether of low (11,000–16,000 MPa∙s), medium (17,000–23,000 MPa∙s), and high (20,000–30,000 MPa) viscosity. The additives were introduced into cement in the amount of 0.25, 0.5, and 0.75 % by weight. It has been established that the introduction of cellulose ether in cement leads to an increase in the normal density of the slurry and extends the duration of the mortar setting. The normal density of cement slurry increases with the introduction of cellulose ethers of low viscosity (LV) and medium viscosity (MV) by 5.4‒16.8 %; when introducing the ether of high viscosity (HV), by 21.3–41.4 %. This confirms the high water-retaining capacity of methyl hydroxyethyl cellulose, which increases with increasing viscosity of the additives. The setting duration of cement slurry increases, depending on the concentration and viscosity of the additives, by 2‒4 times, compared with an additive-free material. There is also a significant reduction in the strength of the cement matrix in the early periods of hardening (1–7 days) depending on the concentration of the additives, by 2.2–4.2 times. The strength of the samples is least affected by the cellulose ether of low viscosity, largest – by that of high viscosity. The reduction of strength is observed at the age of 28 days, although not very much pronounced. Compared to the additive-free cement, the strength amount to: for the ester of low viscosity at concentrations: 0.25 % by weight – 14.3 %, 0.50 % by weight – 23.9 %, 0.75 % by weight – 40.5 %; for the ether of medium viscosity, respectively, 23.8, 26.2, and 33.3 %; for the ether of high viscosity, 28.6; 45.2, and 61.0 %. The corrosion resistance of the cement matrix with methyl hydroxyethyl cellulose additives is increased at a concentration of up to 0.25 % by weight and then gradually decreases. The above results make it possible to recommend using, in the production of dry construction mixtures, the cellulose ethers of low and medium viscosity, which would ensure the required time to maintain the solution mobility and the sufficient strength of the resulting material, Изучено влияние добавки метилгидросиэтилцеллюлозы на технические и физико-механические свойства цементной матрицы. Использовали эфир целлюлозы низкой (11000 – 16000 мПа∙с), средней (17000 – 23000 мПа∙с) и высокой (20000 – 30000 мПа∙с) вязкости. Добавки вводились в цемент в количестве 0,25, 0,5 и 0,75 мас. %. Установлено, что введение эфира целлюлозы в цемент приводит к увеличению нормальной густоты теста и удлинение сроков схватывания растворов. Нормальная густота цементного теста возрастает при введении эфиров целлюлозы низкой (НВ) и средней вязкости (СВ) на 5,4 – 16,8 %, а при введении эфира высокой вязкости (ВВ) на 21,3 – 41,4 %. Это подтверждает высокую водоудерживающую способность метилгидроксиэтилцеллюлозы, которая возрастает с увеличением вязкости добавок. Сроки схватывания цементного теста увеличиваются, в зависимости от концентрации и вязкости добавок, в 2 – 4 раза по сравнению с материалом без добавок. Происходит также значительное снижение прочности цементной матрицы в ранние сроки твердения (1 – 7 суток) в зависимости от концентрации добавок в 2,2 – 4,2 раза. Меньше снижает прочность образцов эфир целлюлозы низкой вязкости, больше всего – высокой. Уменьшение прочности отмечается и в возрасте 28 суток, но не так ощутимо. По сравнению с цементом без добавок, прочность составляет: для эфира низкой вязкости при концентрациях 0,25 мас. % – 14,3 %, 0,50 мас. % – 23,9 %, 0,75 мас. % – 40,5 %, для эфира средней вязкости, соответственно, 23,8; 26,2 и 33,3 %, а для эфира высокой вязкости 28,6; 45,2 и 61,0 %. Коррозионная стойкость цементной матрицы с добавками метилгидроксиэтилцеллюлозы повышается при концентрации до 0,25 мас. %, а затем постепенно снижается. Приведенные результаты позволяют рекомендовать использовать при производстве сухих строительных смесей эфиры целлюлозы низкой и средней вязкости, что обеспечит необходимые сроки сохранения подвижности раствора и достаточную прочность конечного материала, Вивчено вплив добавки метилгідроксиетилцелюлози на технічні та фізико-механічні властивості цементної матриці. Використовували ефір целюлози низької (11000 – 16000 мПа∙с), середньої (17000–23000 мПа∙с) та високої (20000 – 30000 мПа∙с) в’язкості. Добавки вводилися в цемент в кількості 0,25, 0,5 і 0,75 мас. %. Встановлено, що введення ефіру целюлози в цемент призводить до збільшення нормальної густоти тіста і подовження строків тужавлення розчинів. Нормальна густота цементного тіста зростає при введенні ефірів целюлози низької (НВ) і середньої в’язкості (СВ) на 5,4–16,8 %, а при введенні ефіру високої в'язкості (ВВ) на 21,3–41,4 %. Це підтверджує високу водоутримувальну здатність метилгідроксиетилцелюлози, яка зростає із збільшенням в’язкості добавок. Строки тужавлення цементного тіста збільшуються, в залежності від концентрації та в’язкості добавок, в 2–4 рази у порівнянні з матеріалом без добавок. Відбувається також значне зниження міцності цементної матриці в ранні строки тверднення (1–7 діб) в залежності від концентрації добавок в 2,2–4,2 рази. Найменше знижує міцність зразків ефір целюлози низької в’язкості, найбільше – високої. Зменшення міцності відмічається і у віці 28 діб, але не таке відчутне. У порівнянні з цементом без добавок, міцність складає: для ефіру низької в’язкості при концентраціях: 0,25 мас. % – 14,3 %, 0,50 мас. % – 23,9 %, 0,75 мас. % – 40,5 %, для ефіру середньої в’язкості, відповідно, 23,8; 26,2 і 33,3 %, а для ефіру високої в'язкості 28,6; 45,2 і 61,0 %. Корозійна стійкість цементної матриці з добавками метилгідроксиетилцелюлози підвищується при концентрації до 0,25 мас. %, а потім поступово знижується. Наведені результати дозволяють рекомендувати використовувати при виробництві сухих будівельних сумішей ефіри целюлози низької та середньої в’язкості, що забезпечить необхідні строки зберігання рухливості розчину та достатню міцність кінцевого матеріалу

In this paper, an investigation aimed at characterising the behaviour of headed shear studs in push-out testing is presented. The study aims to contribute to the limited knowledge of Pultruded Fibre Reinforced Polymer (PFRP)-concrete composites, highlighting the predominant failure mode and the underlying variables relevant for predictive analytical equations. Two phases of experimental push-out tests were carried out on composite slabs comprising of normal density concrete (NWC), and PFRP connected using steel headed studs. Phase one focused on studying the effects of headed shear stud configuration on the load capacity of the composite slabs, adopting 19 mm diameter studs. Phase two of the study was aimed at characterising the behaviour of the composite slab by varying the headed stud diameters. Two push-out test specimens adopted 12 mm diameter studs, and a third specimen within this phase adopted the 16 mm stud diameter. The dominant failure mode was bearing, net tension and shear out failures of the FRP plates. These modes of failure were distinctly different from those prevalent in the conventional steel-concrete composite, which is either stud shank failure or concrete pull out. The test investigation suggested a successive increase in shear capacity with increased stud sizes. Specimen with stud size of 16 mm attained higher shear strength per stud, approximately 29.4% in comparison to those with 12 mm diameter studs. The study observed that PFRP-concrete composites could mobilise between 40 and 50% shear resistances to that of their steel-concrete counterpart’s. However, the intensity of bearing failure increases with increase in stud size, thereby compromising the ductility of shear connection.

Introduction: there is practically no information on the utilization of ash and slag waste (ASW) application in technology of special (noncontracting, expanding, self-stressing) cements, which predetermines the relevance of research in this direction. The study investigates the properties of experimental samples from cement, ash-and-slag and sand mixtures based on sulphoaluminate Portland cement (SAC) with an additive of the ASW. Materials and methods: a fine-particle binder material consisting of the SAC produced by the Podolsk Cement factory with a fine-grained ASW additive was used to obtain a binder mixture. Silica sand functioned as fine aggregate. All the raw materials used were local to the Russian Federation. The setting time, soundness, and strength of the binder mixture were determined according to GOST 30744-2001 standard. The specific surface area of the Portland cement was established through the use of the air permeability method utilizing of PMTs-500 instrument. The microstructure of the hardened binder mixture was studied employing electron microscopic analysis and X-ray phase analysis. Results: the work investigates the effect of 10 %, 15 %, 20 %, and 50 % ASW additive on the water demand, strength, and setting time of the SAC. The article also explores the kinetics of hardening and structure formation of samples from the binder mixture based on the SAC and ASW for hardening under normal conditions. Conclusions: results of the investigation allow recommending the ASW characterized by high dispersion as an additive for production of special cements without significant reduction of their properties. In the presence of the ASW, setting times of the cement mixtures virtually do not change as compared with the pure SAC. With limiting the amount of the ASW in the composition of the Portland cement, the strength characteristics do not practically change through the entire period of hardening.

In recent years women entrepreneurs have made a significant contribution to the economic growth of most countries. Therefore, at the present stage of the entrepreneurship study, it is relevant to analyze the patterns that characterize the current level of women's entrepreneurial activity as well as determine the sectoral structure of women's entrepreneurship. The purpose of the study is a comprehensive assessment of women's early entrepreneurial activity and their sectoral preferences in creating their own business. In the course of the study, the results of the report on the global monitoring project for female entrepreneurship for the years 2016-2017 as to 74 countries is used. The levels of entrepreneurial activity of women in these countries also reviewed. The sectoral structure of women's entrepreneurship was assessed in five groups including typical types of economic activity by using normal density distribution functions. According to the results of the researches, conclusions were drawn on the predominance of such types of economic activity as trade (46.54%), health care, education and social services (19.22%), management and personal services as (15.70%). The obtained results can be used by entrepreneurs as well as by government bodies related to the business activities regulation. In the article, the original tools for assessing the sectoral structure of women's entrepreneurship is proposed.

Problem statement. Phosphogypsum-based binding materials without pretreatment have poor physical and mechanical characteristics compared to binders made of natural raw materials. This is due to the high value of their specific surface area, which in turn leads to an increase in water demand. Besides, phosphogypsum contains fluorine and phosphorus compounds adversely affecting the final strength. Therefore, neutralization of these compounds and decreasing water demand of phosphogypsum-based gypsum binder is the priority. Based on the preliminary research, we offered a scientific hypothesis of dry neutralization of fluorine and phosphorus compounds in phosphogypsum by an activated silica/calcium carbonate mixture used in the production of phosphogypsum-based binders. Purpose. The research of the effect of various impurities (lime, calcium carbonate, crushed sand, etc.) on gypsum binder obtained from phosphogypsum as well as the improvement of water resistance and manufacturing processes of phosphogypsum-based gypsum binder (setting time, water-to-gypsum ratio, etc.) that mitigate its disadvantages and extend the scope of application. Conclusion. The research has shown that after adding crushed sand and calcium carbonate as neutralizers of water-soluble phosphorus and fluorine impurities can significantly reduce the amount of water-soluble phosphorus compounds and make water-soluble fluorine impurities disappear completely (Table 6), which makes it possible to use phosphogypsum to produce binders that can be used in civil construction. Moreover, this neutralization method almost doesn’t involve emissions of fluoride compounds during the thermal treatment, and besides, physical and mechanical properties of the neutralized phosphogypsum-based hemihydrate CaSO 4 ∙0,5H 2 O correspond to GVF−4 Grade.

Introduction: This study aimed to evaluate the association between the psoas muscle (PM) index with or without fatty infiltration and various indices associated with muscle mass in hemodialysis (HD) patients.Methods: We included stable HD patients (n = 83). The collected data included subjective global assessment (SGA) score, ASM/Ht2 (appendicular skeletal muscle mass divided by the squared height in meters), gait speed (GS; m/s), and handgrip strength (HGS; kg). The abdominal computed tomography (CT) image was obtained using a CT scanner. The PM and normal-density PM (NPM) indices (mm2/m2) were calculated using the whole PM area or the area with an attenuation range of 35–100 HU divided by the squared height in meters.Results: Correlation coefficients for the SGA score, ASM/Ht2, HGS, and GS were greater for the NPM index than for the PM index. The linear regression analysis showed that, on multivariate analysis, the NPM index was significantly associated with the SGA score, ASM/Ht2, and GS. However, the PM index was significantly associated with the SGA score and ASM/Ht2 but not with HGS or GS. For calculating the low GS, the area under the receiver operating characteristic curve area was significantly greater for the NPM index than for the PM index (P = 0.012).Conclusion: The present study suggested that the NPM index excluding fatty infiltration may be an early and useful indicator for detecting muscle strength and physical performance among HD patients.

Since the outbreak of the new coronavirus disease (COVID-19), a large number of scientific studies and data analysis reports have been published in the International Journal of Medicine and Statistics. Taking the estimation of the incubation period as an example, we propose a low-cost method to integrate external research results and available internal data together. By using empirical likelihood method, we can effectively incorporate summarized information even if it may be derived from a misspecified model. Taking the possible uncertainty in summarized information into account, we augment a logarithm of the normal density in the log empirical likelihood. We show that the augmented log-empirical likelihood can produce enhanced estimates for the underlying parameters compared with the method without utilizing auxiliary information. Moreover, the Wilks' theorem is proved to be true. We illustrate our methodology by analyzing a COVID-19 incubation period data set retrieved from Zhejiang Province and summarized information from a similar study in Shenzhen, China.

The pion production mechanism is explored based on the ultrarelativistic quantum molecular dynamics model (UrQMD) in which the $\mathrm{\ensuremath{\Delta}}$-mass dependence of the $\mathcal{M}$ matrix and $\mathrm{\ensuremath{\Delta}}$-mass dependence of the momentum ${p}_{N\mathrm{\ensuremath{\Delta}}}$ in $N\mathrm{\ensuremath{\Delta}}\ensuremath{\rightarrow}NN$ cross sections are taken into account. By analyzing the time evolution of the pion production rate and the density in the overlapped region for the reaction of Au+Au at the beam energy of $0.4A$ GeV, we find that characteristic density of pion observable is in the region of 1--2 times normal density. The process of pion production in the reaction is tracked, including the loops of $NN\ensuremath{\leftrightarrow}N\mathrm{\ensuremath{\Delta}}$ and $\mathrm{\ensuremath{\Delta}}\ensuremath{\leftrightarrow}N\ensuremath{\pi}$, and our calculations show that the sensitivity of ${\ensuremath{\pi}}^{\ensuremath{-}}/{\ensuremath{\pi}}^{+}$ to symmetry energy is weakened after 4--5 $N\text{\ensuremath{-}}\mathrm{\ensuremath{\Delta}}\text{\ensuremath{-}}\ensuremath{\pi}$ loops in the pion production path. The ${\ensuremath{\pi}}^{\ensuremath{-}}/{\ensuremath{\pi}}^{+}$ ratio in the reaction near the threshold energies retains its sensitivity to the symmetry energy, and it is insensitive to the nuclear incompressibility ${K}_{0}$ and effective mass when their values are selected in the commonly accepted range. By comparing the UrQMD calculations to the FOPI data at $0.4A$ GeV and considering the constraint of symmetry energy from neutron star properties, the slope of symmetry energy $L=54--91$ MeV and the symmetry energy at two times normal density $S(2{\ensuremath{\rho}}_{0})=48--59$ MeV are deduced, and they are also consistent with the constraint from the ASY-EOS flow data.

The article studies the effect of complex chemical additives on the water demand of cement, the setting time of the cement paste, the consumption of cement and additives KJ-3 on the viscosity of the concrete mixture, and also determines the normal density of the cement paste without the additive and with the plasticizing additive and the rheological characteristics of the concrete mixture with the additive KJ- 3.

The object of research is organic additives of methyl hydroxyethyl cellulose of medium and high viscosity, namely, their nature of the effect on the physical and mechanical durability under the destructive influence of various sulfate-ionic media. The need to study the nature of the effect of this additive on resistance to an aggressive environment is also associated mainly with the expansion of the types of building mixtures to create competitive products without losing product quality and to improve the mechanical and rheological properties.In the course of the study, cellulose ethers of medium (17000–23000 mPa∙s) and high (20,000–30,000 mP s) viscosity were used. Additives were added to the cement in the amount of 0.25, 0.5 and 0.75 wt. %. It was found that the introduction of cellulose ether into cement leads to an increase in the normal density of the dough and an extension of the setting time of solutions, in turn, affects the process of strength gain of the latter, in comparison with control samples without additives. With the introduction of the additive, the rate of water separation of the mixtures also significantly decreases, indicating the water-retention capacity of the additive. For the concentration of additives in the amount of 0.25 wt. %. This decrease is 2 times less than for control samples. For a concentration of 0.5–0.75 wt. % Water loss is reduced by 3 times compared to samples without additive. Significant changes also occur during the early strength gain of the samples with an increase in the additive concentration. The destructive effect of an aggressive sulfate medium was determined by the change in compressive strength. With prolonged exposure to an aggressive environment on control and test samples, it is noted that the introduction of this additive of organic origin negatively affects the strength characteristics of cement mixtures with cellulose ethers with an increase in the additive content. The above results indicate the advisability of using cellulose ethers of medium viscosity in dry building mixtures as such, which will provide the necessary storage time for the fluidity of the solution and sufficient strength of the final material., Объектом исследования являются органические добавки метилгидроксиетилцеллюлозы средней и высокой вязкости, а именно их характер воздействия на физико-механическую долговечность под разрушающим действием различных сульфат-ионных сред. Необходимость изучения характера влияния данной добавки на устойчивость к воздействию агрессивных сред также в основном связана с расширением ассортимента строительных смесей для создания конкурентоспособной продукции без потери качества продукции и для улучшения механико-реологических свойств.В ходе исследования использовались эфиры целлюлозы средней (17000–23000 мПа∙с) и высокой (20000–30000 мПа∙с) вязкости. Добавки вводились в цемент в количестве 0,25, 0,5 и 0,75 мас. %. Установлено, что введение эфира целлюлозы в цемент приводит к увеличению нормальной густоты теста и удлинению сроков схватывания растворов, что в свою очередь влияет на процесс набора прочности последних, в сравнении с контрольными образцами без добавки. При добавлении добавки также значительно уменьшается показатель водоотделения смесей, что свидетельствует о водоудерживающей способности добавки. Для концентрации добавок в количестве 0,25 масс. % это уменьшение составляет в 2 раза меньше, чем для контрольных образцов. Для концентрации 0,5–0,75 масс. % водоотделение уменьшается в 3 раза, по сравнению с образцами без добавки. Существенные изменения происходят и во время набора ранней прочности образцов при увеличении концентрации добавки. Разрушающее воздействие агрессивной сульфатной среды определялось по изменению прочности на сжатие. При длительном воздействии агрессивной среды на контрольные и проектные образцы отмечалось, что наличие данной добавки органического происхождения негативно влияет на прочностные характеристики цементных смесей с эфирами целлюлозы при росте содержания добавки. Приведенные результаты указывают на целесообразность использования эфиров целлюлозы средней вязкости в сухих строительных смесях как таковых, которые обеспечат необходимые сроки хранения подвижности раствора и достаточную прочность конечного материала., Об’єктом дослідження є органічні добавки метилгідроксиетилцелюлози середньої та високої в’язкості, а саме їх характер впливу на фізико-механічну довговічність під руйнуючою дією різних сульфат-іонних середовищ. Необхідність вивчення характеру впливу даної добавки на стійкість до впливу агресивних середовищ також пов’язана здебільшого через розширення асортименту будівельних сумішей для створення конкурентоспроможної продукції без втрати якості продукції та для поліпшення механіко-реологічних властивостей.У ході дослідження використовувалися ефіри целюлози середньої (17000–23000 мПа∙с) та високої (20000–30000 мПа∙с) в’язкості. Добавки вводилися в цемент в кількості 0,25, 0,5 та 0,75 мас. %. Встановлено, що введення ефіру целюлози в цемент призводить до збільшення нормальної густоти тіста та подовження строків тужавлення розчинів, що у свою чергу впливає на процес набору міцності останніх, в порівнянні до контрольних зразків без добавки. При введенні добавки також значно зменшується показник водовідділення сумішей, що свідчить про водоутримувальну здатність добавки. Для концентрації добавок у кількості 0,25 мас. % це зменшення складає в 2 рази менше, ніж для контрольних зразків. Для концентрації 0,5–0,75 мас. % водовідділення зменшується в 3 рази, в порівнянні із зразками без добавки. Суттєві зміни відбуваються і під час набору ранньої міцності зразків при збільшенні концентрації добавки. Руйнуючий вплив агресивного сульфатного середовища визначався по зміні міцності на стиск. При довготривалому впливі агресивного середовища на контрольні та дослідні зразки відмічається, що введення даної добавки органічного походження негативно впливає на характеристики міцності цементних сумішей з ефірами целюлози при зростанні вмісту добавки. Наведені результати вказують на доцільність використовування ефірів целюлози середньої в’язкості в сухих будівельних сумішах як таких, що забезпечать необхідні строки зберігання рухливості розчину та достатню міцність кінцевого матеріалу.

The Gram-Charlier expansion, where skewness and kurtosis directly appear as parameters, has become popular in finance as a generalization of the normal density. Non-normal skewness and kurtosis of underlying asset of bond issuer company are significantly contributes to the phenomenon of volatility smile. Hermite polynomial is used to get an expansion of the probability distribution. In this paper, Gram-Charlier model is applied to BTPN Bond which is issued in 2017. The result showed that Gram-Charlier model is more consistent than Black-Scholes model when the skewness and kurtosis are taken into account. Keywords: Skewness, Kurtosis, Gram-Charlier, Hermite polynomial

The object of research is cement, which contains in its composition silica of various structures. The increase in the production of composite cements leads to the need to search for new active mineral additives. At the moment, the choice of mineral additives is made without taking into account the state in which the silicate component is located, therefore, it is necessary to develop certain criteria for the targeted selection of possible materials. This will reduce the cost of labor and financial resources to conduct relevant research. As it is known, silicates can be in a crystalline, amorphous and glassy state; therefore, the reactivity of various additives, even with the same chemical composition, can also differ significantly. It is proposed to study the effect of silica structure on hydration processes and properties of cements. The effect of silica in a different phase state (crystalline, amorphous, and glassy) on the hardening processes and physico-mechanical properties of composite cements has been investigated. It is established that the crystallinity degree of silica significantly affects the normal density of cement paste. Thus, the introduction of crystalline silica increases the normal thickness by 0.1–1.1 %, amorphous by 12.3–136.1 %, glassy by 11.2–56.2 %, compared with non-additive cement. The setting time of cement paste varies slightly. In the early stages of hardening, the rate of drop in strength is highest with the introduction of amorphous silica. For example, when enter 10 wt. % of crystalline silica shows a slight increase in the strength of the samples, compared with 8.2 % non-additive cement. The same amount of amorphous silica additive reduces strength by 33 %, glassy silica – by 19.2 %. This trend continues with increasing content of additives. The obtained research results allow to conclude that it is most appropriate to use in the production of composite cements mineral additives containing in their composition silica phases in a crystalline and glassy state.

This paper presents the durability performance of concrete incorporating high-volumes of fly ash exposed to a harsh marine environment for 19 to 24 years. Concrete specimens (305 × 305 × 915 mm [1 × 1 × 3 ft.]) were cast using W/CM in the range of 0.31 to 0.46, various types of fly ash with replacement levels of 56 or 58%, and various types of normal density and lightweight aggregates. Surface erosion/scaling was seen on all specimens; the extent of erosion was slightly worse for fly ash concrete with normal density aggregate compared to the controls (without fly ash), but fly ash concrete with two of the three lightweight aggregates exhibited severe surface erosion. Laboratory testing included taking cores from each block and determining the existing chloride profile, compressive strength and “chloride permeability” (ASTM C1202). The depth of chloride penetration was found to be in excess of 100-mm (4 in.) for the concrete specimens without fly ash, whereas the presence of fly ash significantly decreased the depth of penetration to approximately 30 and 40 mm in specimens containing either normal density or lightweight aggregate, respectively. The increased penetration in the concrete with lightweight aggregates is attributed to the surface erosion observed with these concretes. The results from the chloride permeability testing also indicate significant increases in the resistance to chloride-ion penetration for fly ash concrete.

Background Headless screw fixation is the current gold standard of surgical repair for scaphoid fractures. However, maintaining reduction of certain types of scaphoid fractures is challenging with a compression screw. Plate fixation may offer superior fixation in some scaphoid fractures, particularly those with comminution, nonunion, segmental bony defects, and osteopenic or osteoporotic bone. Purpose This study questions whether method of fixation is a determinant in load to failure in segmental scaphoid fractures, and whether any fixation provides a greater mechanical advantage in simulated normal versus osteoporotic bone. Materials and Methods Polyurethane models were fashioned to simulate scaphoids with 3-mm segmental defects. Defects were bridged by one of three constructs: a locking plate, a nonlocking plate, or a headless compression screw. Three models for each fixation construct were tested for both simulated normal and osteoporotic bone density. Load to failure was recorded as the load at which the 3-mm segmental defect was closed. Results Gap closure occurred in all trials. In simulated normal bone, there were no statistically significant differences in load to failure between fixation methods. In simulated osteoporotic bone, the locking plate had a 28% greater load to failure as compared with screw fixation. Conclusion While biomechanical testing shows that plate and screw fixations are equivalent in normal density bone for fixation of a segmental scaphoid defect, locking plates are superior to screw fixation in simulated osteoporotic bone models. Clinical Relevance Plate fixation may provide superior fixation for complex scaphoid fractures, particularly in osteopenic bone.

Functionally Graded Concrete (FGC) is fabricated at the Institute for Lightweight Structures and Conceptual Design (ILEK) by using a layer-by-layer technique with two different technological procedures: casting and dry spraying. Functional gradations are developed from two reference mixtures with diametrically opposed characteristics in terms of density, porosity, compression strength and elasticity modulus. In this study the first mixture consists of Normal Density Concrete (NDC), with density about 2160 kg⊙m3 while the second mixture helps to obtain a very lightweight concrete, with density about 830 kg⊙m3. The FGC specimens have layers with different alternating porosities and provide superior deformability capacity under bulk compression compared to NDC specimens. In addition, the FGC specimens experienced a graceful failure behaviour, absorbing high amounts of energy during extended compression paths. The porosity variation inside the layout of tested specimens is inspired by the internal structure of sea urchin spines of heterocentrotus mammillatus, a promising role model for energy absorption in biomimetic engineering.

Recent studies have revealed that neutrophils exhibit an unsuspected heterogeneity. In this context, the term high-density neutrophils (HDNs) has recently gained ground to define nothing more than neutrophils displaying an unaltered normal density. Therefore, as discussed here, we argue that the HDNs term must be avoided, as it is confounding and scientifically inappropriate.

Постановка проблеми. Гіпсові в'яжучі речовини, отримані з фосфогіпсу без попередньої обробки, мають низькі фізико-механічні показники порівняно з в'яжучими, отриманими з природної сировини. Це пов'язано з їх високою питомою поверхнею, що, у свою чергу, підвищує водопотребу. Крім того, у фосфогіпсі присутні також сполуки фтору і фосфору, які негативно впливають на кінцеву міцність. Тому нейтралізація цих сполук і зменшення водопотреби гіпсового в'яжучого, отриманого із фосфогісу, постає приорітетним завданням. На підставі попередніх досліджень ми запропонували наукову гіпотезу, яка полягає в сухій нейтралізації фосфорних і фтористих сполук фосфогіпсу активованою сумішшю кремнезему і карбонату кальцію для виробництва гіпсових в'яжучих на основі фосфогіпсу. Мета статті ‑ дослідження впливу різних домішок (вапна, карбонату кальцію і меленого піску) на гіпсове в’яжуче, одержане із фосфогіпсу, а також підвищення водостійкості та поліпшення технологічних факторів в’яжучого на основі фосфогіпсу (час тверднення, водогіпсове відношення та ін.), що зменшить його недоліки та розширить сферу застосування. Висновок. Дослідження показали, що введення меленого піску і карбонату кальцію як нейтралізаторів водорозчинних домішок фосфору і фтору дозволяє значно знизити кількість водорозчинних фосфорних сполук, а водорозчинні домішки фтору зникають повністю (табл. 6), що дозволяє використовувати фосфогіпс для одержання в'яжучих, які можна використовувати в цивільному будівництві. Крім того, за даного методу нейтралізації практично відсутні виділення фтористих сполук під час теплової обробки, а фізико-механічні властивості напівгідрату CaSO4 ∙ 0,5H2O на основі нейтралізованого фосфогіпсу відповідають марці ГВФ−4., Постановка проблемы. Гипсовые вяжущие вещества, полученные из фосфогипса без предварительной обработки, имеют низкие физико-механические показатели по сравнению с вяжущими, полученными из природного сырья. Это связано с их высокой удельной поверхностью, что, в свою очередь, ведет к повышению водопотребности. Кроме того, в фосфогипсе присутствуют также соединения фтора и фосфора, которые негативно влияют на конечную прочность. Поэтому нейтрализация этих соединений и уменьшение водопотребности гипсового вяжущего, полученного из фосфогиса, являются приоритетным заданием. На основании предварительных исследований нами предложена научная гипотеза, которая заключается в сухой нейтрализации фосфорных и фтористых соединений фосфогипса активированной смесью кремнезема и карбоната кальция для производства гипсовых вяжущих на основе фосфогипса. Цель статьи ‑ исследование влияния различных примесей (извести, карбоната кальция и молотого песка) на гипсовое вяжущее, полученное из фосфогипса, а также повышение водостойкости и улучшение технологических факторов вяжущего на основе фосфогипса (время твердения, водогипсове отношение и пр.), что уменьшит его недостатки и расширит сферу применения. Вывод. Исследования показали, что введение молотого песка и карбоната кальция в качестве нейтрализаторов водорастворимых примесей фосфора и фтора позволяет значительно снизить количество водорастворимых фосфорных соединений, а водорастворимые примеси фтора исчезают полностью (табл. 6), что позволяет использовать фосфогипс для получения вяжущих, которые можно использовать в гражданском строительстве. Кроме того, при данном методе нейтрализации практически отсутствуют выделения фтористых соединений при тепловой обработке, а физико-механические свойства полугидрат CaSO4 ∙ 0,5H2O на основе нейтрализованного фосфогипса соответствуют марке ГВФ−4., Problem statement. Phosphogypsum-based binding materials without pretreatment have poor physical and mechanical characteristics compared to binders made of natural raw materials. This is due to the high value of their specific surface area, which in turn leads to an increase in water demand. Besides, phosphogypsum contains fluorine and phosphorus compounds adversely affecting the final strength. Therefore, neutralization of these compounds and decreasing water demand of phosphogypsum-based gypsum binder is the priority. Based on the preliminary research, we offered a scientific hypothesis of dry neutralization of fluorine and phosphorus compounds in phosphogypsum by an activated silica/calcium carbonate mixture used in the production of phosphogypsum-based binders. Purpose. The research of the effect of various impurities (lime, calcium carbonate, crushed sand, etc.) on gypsum binder obtained from phosphogypsum as well as the improvement of water resistance and manufacturing processes of phosphogypsum-based gypsum binder (setting time, water-to-gypsum ratio, etc.) that mitigate its disadvantages and extend the scope of application. Conclusion. The research has shown that after adding crushed sand and calcium carbonate as neutralizers of water-soluble phosphorus and fluorine impurities can significantly reduce the amount of water-soluble phosphorus compounds and make water-soluble fluorine impurities disappear completely (Table 6), which makes it possible to use phosphogypsum to produce binders that can be used in civil construction. Moreover, this neutralization method almost doesn’t involve emissions of fluoride compounds during the thermal treatment, and besides, physical and mechanical properties of the neutralized phosphogypsum-based hemihydrate CaSO4∙0,5H2O correspond to GVF−4 Grade.

This paper investigates the time-varying conditional higher moments of the daily returns on WTI crude oil futures, using the GJR-GARCH model with Gram-Charlier expansion (GCE) of normal density. The empirical results suggest significant time-variations in the conditional skewness and kurtosis. The out-of-sample value-at-risk (VaR) forecasting results show the advantage of models with dynamic higher moments over those with constant higher moments.

Thermophysical properties such as electron transport coefficients, ion composition, pressure, and internal energy are calculated for the plasma of titanium and zinc with densities 10–20 times less than normal density and at temperatures of 10–60 kK. The relaxation-time approximation and the generalized chemical model are used for calculations. The results obtained are compared with the data of experiments and calculation results of other researchers. For titanium, a good agreement with available experimental data and results of calculations by other models, including the first-principles calculations, is obtained, whereas, for zinc, a discrepancy between results of theoretical models and data of measurements for electrical conductivity is observed, which does not yet have an explanation.

Simulations play an increasing role in metrology and analytical chemistry, particularly the use of simulated normal distributions. Microsoft Excel is available to almost everybody and normal distributions can be simulated using either an innate function or other algorithms. We explore the success of five different algorithms to simulate normal distributions and compare the outcome with a simulation coded in R. The normality of 106 data points simulated by the chosen algorithms was tested by different recognized statistical procedures and Q–Q plots. They all failed the statistical procedures, but evaluating the Q–Q plots revealed different types of deviations. It also showed that the deviations, although statistically significant, most likely do not have any practical relevance in laboratory work.

Let C(0,t) denote a generalized Wiener space, the space of real-valued continuous functions on the interval (0,t) and define a random vector Zn : C(0,t) → R n by Zn(x) = ( R t 1 0 h(s)dx(s),..., R tn 0 h(s)dx(s)), where 0 < t1 < ··· < tn < t is a partition of (0,t) and h ∈ L2(0,t) with h 6 0 a.e. In this paper we will introduce a simple formula for a generalized conditional Wiener integral on C(0,t) with the conditioning function Zn and then evaluate the generalized analytic conditional Wiener and Feynman integrals of the cylinder function F(x) = f( R t 0 e(s)dx(s)) for x ∈ C(0,t), where f ∈ Lp(R)(1 ≤ p ≤ ∞) and e is a unit element in L2(0,t). Finally we express the generalized analytic conditional Feynman integral of F as two kinds of limits of non-conditional generalized Wiener integrals of polygonal functions and of cylinder functions using a change of scale transformation for which a normal density is the kernel. The choice of a complete orthonormal subset of L2(0,t) used in the transformation is independent of e and the conditioning function Zn does not contain the present positions of the generalized Wiener paths.

Визначено нормальну густоту та терміни тужавіння безклінкерного композиційного гіпсовапняного в’яжучого за різних водотвердих відношень. Досліджено фізико-механічні та експлуатаційні показники каменю. Визначено зміну відносного розширення каменю в часі. Встановлено, що в системі “гіпс – негашене вапно – метакаолін” найбільшою міцністю та водостійкістю характеризується камінь, до складу в’яжучого якого входить будівельний гіпс марки Г-5. Методом ДТА досліджено фізико-хімічні процеси під час нагрівання каменю, який тверднув у повітряно-сухих умовах протягом 1 року. Методом РФА встановлено фазовий склад продуктів гідратації. The normal density and curing terms of without clinker composite gypsum-lime binder at different water/binder ratios were determined. The physical and mechanical and working parameters of stone were investigated. The change of stone relative extension in time was determined. It was established that in the system “gypsum – quicklime – metakaolin” the greatest strength and water resistance has stone, the composition of the binder includes building gypsum of brand G-5. The physical and chemical processes during the stone heating, which hardened in air-dry conditions for 1 year, were investigated using DTA. The phase composition of hydration products was established using XRD.

Minimum density power divergence estimation provides a general framework for robust statistics, depending on a parameter &alpha, which determines the robustness properties of the method. The usual estimation method is numerical minimization of the power divergence. The paper considers the special case of linear regression. We developed an alternative estimation procedure using the methods of S-estimation. The rho function so obtained is proportional to one minus a suitably scaled normal density raised to the power &alpha, We used the theory of S-estimation to determine the asymptotic efficiency and breakdown point for this new form of S-estimation. Two sets of comparisons were made. In one, S power divergence is compared with other S-estimators using four distinct rho functions. Plots of efficiency against breakdown point show that the properties of S power divergence are close to those of Tukey&rsquo, s biweight. The second set of comparisons is between S power divergence estimation and numerical minimization. Monitoring these two procedures in terms of breakdown point shows that the numerical minimization yields a procedure with larger robust residuals and a lower empirical breakdown point, thus providing an estimate of &alpha, leading to more efficient parameter estimates.

Overlap coefficient (OVL) represents the proportion of overlap between two probability distributions, as a measure of the similarity between them. In this paper, we define a new overlap coefficient Λ based on KullbackLeibler divergence and compare its performance to three known overlap coefficients, namely Matusia’s Measure ρ, Morisita’s Measure λ, Weitzman’s Measure δ. We study their properties, relations between them, and give approximate expressions for the biases and the variances.

The object of research is cement, which contains in its composition silica of various structures. The increase in the production of composite cements leads to the need to search for new active mineral additives. At the moment, the choice of mineral additives is made without taking into account the state in which the silicate component is located, therefore, it is necessary to develop certain criteria for the targeted selection of possible materials. This will reduce the cost of labor and financial resources to conduct relevant research.As it is known, silicates can be in a crystalline, amorphous and glassy state; therefore, the reactivity of various additives, even with the same chemical composition, can also differ significantly. It is proposed to study the effect of silica structure on hydration processes and properties of cements.The effect of silica in a different phase state (crystalline, amorphous, and glassy) on the hardening processes and physico-mechanical properties of composite cements has been investigated. It is established that the crystallinity degree of silica significantly affects the normal density of cement paste. Thus, the introduction of crystalline silica increases the normal thickness by 0.1–1.1 %, amorphous by 12.3–136.1 %, glassy by 11.2–56.2 %, compared with non-additive cement. The setting time of cement paste varies slightly.In the early stages of hardening, the rate of drop in strength is highest with the introduction of amorphous silica. For example, when enter 10 wt. % of crystalline silica shows a slight increase in the strength of the samples, compared with 8.2 % non-additive cement. The same amount of amorphous silica additive reduces strength by 33 %, glassy silica – by 19.2 %. This trend continues with increasing content of additives.The obtained research results allow to conclude that it is most appropriate to use in the production of composite cements mineral additives containing in their composition silica phases in a crystalline and glassy state., Об'єктом дослідження є цемент, який містить в своєму складі кремнезем різної структури. Збільшення об’ємів випуску композиційних цементів призводить до необхідності пошуку нових активних мінеральних добавок. На даний момент вибір мінеральних добавок проводиться без урахування стану, в якому знаходиться силікатна складова, тому потрібна розробка певних критеріїв для цілеспрямованого підбору можливих матеріалів. Це дозволить знизити витрати трудових та фінансових ресурсів на проведення відповідних досліджень. Як відомо, силікати можуть знаходитися в кристалічному, аморфному та скловидному стані, тому реакційна здатність різних добавок, навіть при однаковому хімічному складі, також може суттєво відрізнятися. Було запропоновано вивчити вплив структури кремнезему на процеси гідратації та властивості цементів.Досліджено вплив кремнезему в різному фазовому стані (кристалічному, аморфному та скловидному) на процеси тверднення та фізико-механічні властивості композиційних цементів. Встановлено, що ступінь кристалічності кремнезему суттєво впливає на нормальну густоту цементного тіста. Так, введення кристалічного кремнезему підвищує нормальну густоту на 0,1–1,1 %, аморфного на 12,3–136,1 %, скловидного на 11,2–56,2 %, у порівнянні з бездобавочним цементом. Строки тужавлення цементного тіста змінюється несуттєво. В ранні строки тверднення швидкість падіння міцності найвища при введенні аморфного кремнезему. Наприклад, при введенні 10 мас. % кристалічного кремнезему відмічається деяке зростання міцності зразків, у порівнянні з бездобавочним цементом на 8,2 %. Така ж кількість добавки аморфного кремнезему знижує міцність на 33 %, скловидного кремнезему – на 19,2 %. Ця тенденція зберігається і при збільшенні вмісту добавок.Отримані результати досліджень дозволяють зробити висновок, що найбільш доцільно використовувати при виробництві композиційних цементів мінеральні добавки, які містять в своєму складі кремнеземисті фази в кристалічному і скловидному стані., Объектом исследования является цемент, который содержит в своем составе кремнезем различной структуры. Увеличение объемов выпуска композиционных цементов приводит к необходимости поиска новых активных минеральных добавок. На данный момент выбор минеральных добавок проводится без учета состояния, в котором находится силикатная составляющая, поэтому необходима разработка определенных критериев для целенаправленного подбора возможных материалов. Это позволит снизить затраты трудовых и финансовых ресурсов на проведение соответствующих исследований.Как известно, силикаты могут находиться в кристаллическом, аморфном и стекловидном состоянии, поэтому реакционная способность различных добавок, даже при одинаковом химическом составе, также может существенно отличаться. Было предложено изучить влияние структуры кремнезема на процессы гидратации и свойства цементов.Исследовано влияние кремнезема в разном фазовом состоянии (кристаллическом, аморфном и стекловидном) на процессы твердения и физико-механические свойства композиционных цементов. Установлено, что степень кристалличности кремнезема существенно влияет на нормальную густоту цементного теста. Так, введение кристаллического кремнезема повышает нормальную густоту на 0,1–1,1 %, аморфного на 12,3–136,1 %, стекловидного на 11,2–56,2 %, в сравнении с бездобавочным цементом. Сроки схватывания цементного теста изменяются не существенно. В ранние сроки твердения скорость падения прочности наивысшая при введении аморфного кремнезема. Например, при введении 10 мас. % кристаллического кремнезема отмечается некоторое увеличение прочности образцов, в сравнении с бездобавочным цементом, на 8,2 %. Такое же количество добавки аморфного кремнезема снижает прочность на 33,0 %, стекловидного кремнезема на 19,2 %. Эта тенденция сохраняется и при увеличении содержания добавок.Полученные результаты исследования позволяют сделать вывод, что наиболее целесообразно использовать при производстве композиционных цементов минеральные добавки, которые содержат в своем составе кремнеземсодержащие фазы в кристаллическом и стекловидном состоянии.

As next-generation sequencing technology advances and the cost decreases, whole genome sequencing (WGS) has become the preferred platform for the identification of somatic copy number alteration (CNA) events in cancer genomes. To more effectively decipher these massive sequencing data, we developed a software program named SEG, shortened from the word “segment”. SEG utilizes mapped read or fragment density for CNA discovery. To reduce CNA artifacts arisen from sequencing and mapping biases, SEG first normalizes the data by taking the log2-ratio of each tumor density against its matching normal density. SEG then uses dynamic programming to find change-points among a contiguous log2-ratio data series along a chromosome, dividing the chromosome into different segments. SEG finally identifies those segments having CNA. Our analyses with both simulated and real sequencing data indicate that SEG finds more small CNAs than other published software tools. Keywords: SEG, Somatic Copy Number Alteration, Whole Genome Sequencing, Cancer

Background: Temporal incidence patterns provide a crucial window into the dynamics of emerging infectious diseases, yet their utility is limited by the spatially aggregated form in which they are often presented. Weekly incidence data from the 2015-2016 Zika epidemic were available only at the national level for most countries in the Americas. One exception was Colombia, where data at departmental and municipal scales were made publicly available in real time, providing an opportunity to assess the degree to which national-level data are reflective of temporal patterns at local levels. Methods: To characterize differences in epidemic trajectories, our analysis centered on classifying proportional cumulative incidence curves according to six features at three levels of spatial aggregation. This analysis used the partitioning around medoids algorithm to assign departments and municipalities to groups based on these six characteristics. Examination of the features that differentiated these groups and exploration of their temporal and spatial patterns were performed. Simulations from a stochastic transmission model provided data that were used to assess the extent to which groups identified by the classification algorithm could be associated with differences in underlying drivers of transmission. Results: The timing of departmental-level epidemic peaks varied by three months, and departmental-level estimates of the time-varying reproduction number, R(t), showed patterns that were distinct from a national-level estimate. The classification algorithm identified moderate support for two to three clusters at the departmental level and somewhat stronger support for this at the municipal level. Variability in epidemic duration, the length of the tail of the epidemic, and the consistency of cumulative incidence data with a cumulative normal distribution function made the greatest contributions to distinctions across these groups. Applying the classification algorithm to simulated data showed that municipalities with basic reproduction number, R0, greater than 1 were consistently associated with a particular group. Municipalities with R0 < 1 displayed more diverse patterns, although in this case that may be due to simplifications of how the model represented spatial interaction among municipalities. Conclusions: The diversity of temporal incidence patterns at local scales uncovered by this analysis underscores the value of spatially disaggregated data and the importance of locally tailored strategies for responding to emerging infectious diseases.