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1
McDougall, Robert. "A generalisation of the lower radical class." Bulletin of the Australian Mathematical Society 59, no. 1 (February 1999): 139–46. http://dx.doi.org/10.1017/s000497270003269x.
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In this work we demonstrate that the lower radical class construction on a homomorphically closed class of associative rings generates a radical class for any class of associative rings. We also give a new description of the upper radical class using the construction on an appropriate generating class.
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Sands, A. D. "On the lower radical construction of Tangeman and Kreiling." Proceedings of the Edinburgh Mathematical Society 33, no. 2 (June 1990): 203–5. http://dx.doi.org/10.1017/s0013091500018137.
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Zhang, Zhirang, and Xuemei Li. "The Upper Radical Property and Lower Radical Property of Groups." Algebra Colloquium 18, no. 04 (December 2011): 693–700. http://dx.doi.org/10.1142/s100538671100054x.
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We take in this paper an arbitrary class [Formula: see text] of groups as a base, and define a radical property 𝒫 for which every group in [Formula: see text] is 𝒫-semisimple. This is called the upper radical property determined by the class [Formula: see text]. At the same time, we define a radical property 𝒫 for which every group in [Formula: see text] is a 𝒫-radical group. This is called the first lower radical property determined by the class [Formula: see text]. Also, we give another construction leading to the second lower radical property which is proved to be identical with the first one.
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Vigus, Meagan. "Antipassive constructions: Correlations of form and function across languages." Linguistic Typology 22, no. 3 (October 25, 2018): 339–84. http://dx.doi.org/10.1515/lingty-2018-0013.
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Abstract This paper presents a cross-linguistic investigation of the antipassive within the framework of Radical Construction Grammar. Based on function, this study identifies constructions in 70 languages from 25 language families and four geographical macro areas. Iconically motivated correlations were found between functions and the morphosyntactic strategies they employ. The results of this study suggest that constructions indicating the lower individuation of patients and constructions indicating the lower affectedness of patients, previously grouped together as ‘antipassive’, should be considered two separate construction types. This is based on their separate functions, the distinct morphosyntactic strategies used to encode them across languages, and differences in productivity with regard to semantic classes of verbs.
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Veldsman, Stefan. "Sufficient conditions for a well-behaved Kurosh-Amitsur radical theory." Proceedings of the Edinburgh Mathematical Society 32, no. 3 (October 1989): 377–94. http://dx.doi.org/10.1017/s0013091500004648.
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Kurosh-Amitsur radical theories have been developed for various algebraic structures. Whenever the notion of a normal substructure is not transitive, this causes quite some problems in obtaining satisfactory general results. Some of the more important questions concerning the general theory of radicals are whether semisimple classes are hereditary, do radical classes satisfy the ADS-property, can semisimple classes be characterized by closure conditions (e.g., is semisimple=coradical), is Sands' Theorem valid and lastly, does the lower radical construction terminate. For associative and alternative rings, all these questions have positive answers. The method of proof is the same in both cases. In [15], Puczylowski used the results of Terlikowska-Oslowska [18, 19] and hinted at a condition which is crucial in obtaining the positive answers to the above questions.
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Fang, Honghin, and Patrick Stewart. "Radical Theory for Granded Rings." Journal of the Australian Mathematical Society. Series A. Pure Mathematics and Statistics 52, no. 2 (April 1992): 143–53. http://dx.doi.org/10.1017/s1446788700034315.
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AbstractIn this paper we propose a general setting in which to study the radical theory of group graded rings. If is a radical class of associative rings we consider two associated radical classes of graded rings which are denoted by G and ref. We show that if is special (respectively, normal), then both G and ref are graded special (respectively, graded normal). Also, we discuss a graded version of the ADS theorem and the termination of the Kurosh lower graded radical construction.
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ANDRUSZKIEWICZ, R. R., and M. SOBOLEWSKA. "ON THE STABILISATION OF ONE-SIDED KUROSH’S CHAINS." Bulletin of the Australian Mathematical Society 86, no. 3 (February 23, 2012): 473–80. http://dx.doi.org/10.1017/s0004972712000068.
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Andruszkiewicz, R. R. "On accessible subrings of associative rings." Proceedings of the Edinburgh Mathematical Society 35, no. 1 (February 1992): 101–7. http://dx.doi.org/10.1017/s0013091500005356.
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We describe for every natural n the class of rings R such that if R is an accessible (left accessible) subring of a ring then R is an n-accessible (n-left-accessible) subring of the ring. This is connected with the problem of the termination of Kurosh's construction of the lower (lower strong) radical. The result for n = 2 was obtained by Sands in a connection with some other questions.
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Sun, Hong Yao, Zheng Yang, Gao Xia Sun, and Xue Feng Xu. "The Research of Silane Oligomer with Lower Valatilization Rate for Protecting Concrete." Applied Mechanics and Materials 357-360 (August 2013): 1318–22. http://dx.doi.org/10.4028/www.scientific.net/amm.357-360.1318.
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As one of the measures to improve the durability of concrete, silane penetrating hydrophobic agents can preserve the properties of respiratory function of concrete and can prevent the penetration from harmful medium such as chloride ions. Because of low molecular weight of the silane penetrating hydrophobic agent such as isobutyl triethoxysilane, high volatilization rate of silane can result in waste of material in construction process. The silane oligomer was obtained by radical polymerization reaction with suitable monomers, initiators and reaction conditions. Furthermore, we verified the structure of the silane oligomer by FT-IR spectroscopy and got its molecular weight by GPC(Gel Permeation Chromatography). The silane oligomer with lower volatilization rate has excellent properties of hydrophobicity, higher penetration depth and resistance to chloride ions penetration.
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Lobera, Josep. "Migrants and 'Patria'. The imagined community of the radical left in Spain." Teknokultura. Revista de Cultura Digital y Movimientos Sociales 17, no. 1 (January 29, 2020): 59–68. http://dx.doi.org/10.5209/tekn.66912.
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The emergence of inclusive populist parties disputes the social construction of the ‘people’ to the exclusive populism, recently generating new academic debates. Do the new radical left parties have a nationalist character? Are populism and nationalism two inseparable dimensions? Drawing on an original dataset in Spain, this article shows that Podemos’ supporters are significantly less nationalist, expressing more open attitudes towards cultural diversity and immigration, and lower levels of Spanishness than voters from other parties. Arguably, Podemos operates as an antagonistic political option to the traditional positions of the populist radical right (PRR), building an inclusive imagined community around a type of constitutional patriotism or republican populism. These findings contribute to the scholar debate on the relationship of nationalism and populism, bringing to discussion the core values of the supporters of a populist party as a complementary element to its categorization.
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Pejcic, T., J. Hadzi-Djokic, B. Markovic, N. Lalic, and B. Glisic. "What are the possible reasons for urethral PSA varieties after radical prostatectomy?" Acta chirurgica Iugoslavica 57, no. 2 (2010): 31–35. http://dx.doi.org/10.2298/aci1002031p.
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Objective: To examine the possible reasons for great varieties in urethral prostate specific antigen (urPSA) levels, in patients after radical prostatectomy (RP). Materials and methods: In 46 patients with prostate cancer, PSA, urPSA, total testosterone, body-mass index (BMI) and the stage of androgenic alopecia (AGA) were determined. Forty-five patients underwent retropubic RP, while one underwent cystoprostatectomy with orthotopic bladder construction, due to bladder cancer. Results: Average patients age prior to surgery plus or minus standard deviation was 65.2+5.8 years. Average urPSA was 20.9+47.5 ng/ml (0.05 to 212 ng/ml, median 2.24 ng/ml). With urethral PSA cut-off of 2.0 ng/ml, two groups were formed: A (urPSA < 2.0 ng/ml) and B (urPSA = 2.0 ng/ml). Patients in the group A had significantly lower average AGA score, than the patients from the group B (2.4+1.3 vs. 4.4+2.2, p=0.0003). In addition, patients from the group A had significantly lower postoperative PSA (0.07+0.08 ng/ml vs. 0.14 + 0.06 ng/ml, p=0.0014). Conclusions: The patients with higher urPSA have higher AGA scores and higher postoperative PSA. This phenomenon is probably the consequence of higher local dihydrotestosterone activity in the scalp and PSA-secreting urethral glands.
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Diedkov, А. G., and V. Yu Коstiuk. "Reconstruction of pelvic ring, using the metal polymer еndoprosthesis after radical internal resection of pelvis." Klinicheskaia khirurgiia 86, no. 5 (May 5, 2019): 54–58. http://dx.doi.org/10.26779/2522-1396.2019.05.54.
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Objective. Investigation of the treatment results and quality of life in the patients, suffering pelvic bones tumors after radical surgical interventions.
Маterials and methods. Results of treatment of 28 patients after organ-preserving operations and of 26 patients after interventions with the lower extremity excision were analyzed.
Results. Median index of the lower extremity function in accordance to the MTS scale after resection have constituted (61.06 ± 15.83)%. The quality of life indices in accordance to FIM questionnaire in the patients after organ-preserving operations - (110.85 ± 13.49) points and the extremity amputation - (106.73 ± 11.97) points did not differ essentially (р = 0.12 in accordance to Mann-Whitney). The pain syndrome degree in accordance to visual-analogue scale in the patients after organ-preserving operations was estimated at average in (1.82 ± 1.56) points, after the extremity amputation - at average in (1.42 ± 0.58) points, what did not differ essentially (р = 0.6 in accordance to Mann-Whitney). The implants survival in 1 mo have constituted (60.7 ± 9.2)%, in one year - (53.6 ± 9.2)%.
Conclusion. The pelvic ring reconstruction, using metal polymer construction constitutes a secure method. It is possible to improve the quality of life after performance of internal resection of pelvic bones with the extremity preservation, using individualization of the patients selection for performance of such interventions.
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Park, Jin Hwan, and Seok-Ho Hwang. "Construction and Characterization of Polyolefin Elastomer Blends with Chemically Modified Hydrocarbon Resin as a Photovoltaic Module Encapsulant." Polymers 14, no. 21 (October 31, 2022): 4620. http://dx.doi.org/10.3390/polym14214620.
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In this study, polyolefin elastomer (POE) was blended with a chemically modified hydrocarbon resin (m-HCR), which was modified through a simple radical grafting reaction using γ-methacryloxypropyl trimethoxy silane (MTS) as an adhesion promotor to the glass surface, to design an adhesion-enhanced polyolefin encapsulant material for photovoltaic modules. Its chemical modification was confirmed by 1H and 29Si NMR and FT-IR. Interestingly, the POE blends with the m-HCR showed that the melting peak temperature (Tm) was not changed. However, Tm shifted to lower values with increasing m-HCR content after crosslinking. Additionally, the mechanical properties did not significantly differ with increasing m-HCR content. Meanwhile, with increasing m-HCR content in the POE blend, the peel strength increased linearly without sacrificing their transmittance. The test photovoltaic modules comprising the crosslinked POE blend encapsulants showed little difference in the electrical performance after manufacturing. After 1000 h of damp-heat exposure, no significant power loss was observed.
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COOKE, GUY J. "ON LOWER RADICAL TYPE CONSTRUCTIONS." Bulletin of the Australian Mathematical Society 83, no. 3 (March 22, 2011): 520–21. http://dx.doi.org/10.1017/s0004972711002061.
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Liu, Hanbing, Xirui Wang, Guojin Tan, Xin He, and Guobao Luo. "System Reliability Evaluation of Prefabricated RC Hollow Slab Bridges Considering Hinge Joint Damage Based on Modified AHP." Applied Sciences 9, no. 22 (November 12, 2019): 4841. http://dx.doi.org/10.3390/app9224841.
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The prefabricated reinforced concrete (RC) hollow slab bridges, with the advantages of high quality, lower cost and shorter construction period, have been widely used for small-to-medium-span highway bridges in China. Because of environmental deterioration and traffic volume increases, the performance of the bridge system deteriorates gradually. Accurate bridge system evaluation can provide a reliable basis for maintenance and management. A bridge system is composed of multiple interrelated components, which makes the system reliability evaluation become a computationally intractable work. In this paper, an effective method was proposed to evaluate the system reliability of the prefabricated RC hollow slab bridge considering hinge joint damage based on the modified analytic hierarchy process (AHP). Considering the subjectivity of the traditional AHP method in constructing the judgment matrix, this paper proposed an objective construction method of the judgment matrix to modify the traditional AHP. The modified hinge plate method (MHPM) proposed by the previous research was utilized to analyze the effect of hinge joint damage on system reliability. In order to verify the applicability of the proposed system reliability evaluation method, a simply supported RC hollow slab bridge was selected as the case study and the system reliability indexes were compared with the traditional series and parallel methods. The results indicated that the traditional methods were either too conservative or too radical to objectively evaluate the actual system reliability level of the structure. In contrast, the proposed method in this paper was more suitable for evaluating the system reliability of such bridges, and more accurate in providing maintenance decision makers with a relatively reasonable bridge condition information.
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Chen, Wanwen, Hao Cheng, and Wenshui Xia. "Construction of Polygonatum sibiricum Polysaccharide Functionalized Selenium Nanoparticles for the Enhancement of Stability and Antioxidant Activity." Antioxidants 11, no. 2 (January 26, 2022): 240. http://dx.doi.org/10.3390/antiox11020240.
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Although selenium nanoparticles (SeNPs) have attracted great attention due to their potential antioxidant activity and low toxicity, the application of SeNPs is still restricted by their poor stability. A combination of polysaccharides and SeNPs is an effective strategy to overcome the limitations. In this study, Polygonatum sibiricum polysaccharide (PSP) was used as a stabilizer to fabricate SeNPs under a simple redox system. Dynamic light scattering, transmission electron microscopy, energy dispersive X-ray, ultraviolet-visible spectroscopy, Fourier transform infrared, and X-ray photoelectron spectrometer were applied to characterize the synthesized PSP-SeNPs. The stability and the antioxidant activity of PSP-SeNPs were also investigated. The results revealed that the zero-valent and well-dispersed spherical PSP-SeNPs with an average size of 105 nm and a negative ζ-potential of −34.9 mV were successfully synthesized using 0.1 mg/mL PSP as a stabilizer. The prepared PSP-SeNPs were stable for 30 days at 4 °C. The decoration of the nanoparticle surface with PSP significantly improved the free radical scavenging ability of SeNPs. Compared to the H2O2-induced oxidative stress model group, the viability of PC-12 cells pretreated with 20 μg/mL PSP-SeNPs increased from 56% to 98%. Moreover, PSP-SeNPs exhibited a higher protective effect on the H2O2-induced oxidative damage on PC-12 cells and lower cytotoxicity than sodium selenite and SeNPs. In summary, these results suggest the great potential of PSP-SeNPs as a novel antioxidant agent in the food or nutraceuticals area.
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do Nascimento, Otávio Luiz, Alexandra Ancelmo Piscitelli Mansur, and Herman Sander Mansur. "“Cement-Free Product” for Settlement of Ceramic Tiles: An Approach for Greener Construction." Materials Science Forum 805 (September 2014): 403–8. http://dx.doi.org/10.4028/www.scientific.net/msf.805.403.
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Increased public awareness of the threats posed by global warming has led to greater concern over the impact of anthropogenic carbon emissions on the global climate associated with the level of carbon dioxide (CO2) in the atmosphere. Hence, without radical market, technological, and cultural changes, the CO2 concentrations are expected to rise to unbearable levels within just few decades ahead. The production of cement is estimated to be responsible for approximately 5% of the global carbon dioxide emissions. Consequently, aiming for creating a more sustainable world, engineers and scientists must develop and put into use greener building materials that may revolutionize the entire construction industry. This study presents an innovative product for settlement of ceramic tiles as a potential alternative for replacing the conventional cement based mortar in some specific building applications. Essentially, the novel system is based on a double face polymer-adhesive sheet (“cement-free product”). Thus, the main goal was to evaluate the performance and estimate the durability of the developed system. Pull-off tests were conducted in order to compare this new system to the traditional one, with polymer modified mortar, under different procedures and conditions of cure. In addition, both systems were modeled using Finite Element Method (FEM) to obtain the stresses at the interface between ceramic-tile and adhesive. Based on the results, the recommended limits of bond strength for the innovative “cement-free product” of ceramic tile installation could be lower than those specifications used for the equivalent mortar systems. Therefore, these results give some preliminary evidence that by using the new “cement-free” product for ceramic-tile installation may lead to some increase in the productivity and, more important, in the sustainability of a relevant sector of the construction industry.
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Eriksson, Per Erik, and Henrik Szentes. "Managing the tensions between exploration and exploitation in large construction projects." Construction Innovation 17, no. 4 (October 20, 2017): 492–510. http://dx.doi.org/10.1108/ci-05-2016-0032.
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Purpose Prior studies highlight the importance of building ambidextrous capabilities to achieve both exploitation of current knowledge and technologies to make profits today, and exploration of new knowledge and technologies to adapt to and prepare for tomorrow’s demands. In spite of its theoretical and practical importance, research on organizational ambidexterity in project-based organizations is scarce. Thus, the purpose of the paper is to study how ambidexterity may be managed and how exploration and exploitation may be achieved in construction projects. The research identifies some drivers and barriers to exploration and exploitation and also sheds light on how various management approaches interact and affect exploration and exploitation activities. Design/methodology/approach The empirical material is drawn from 40 semi-structured interviews with managers representing the client, the contractor and the designer involved in each of the seven large construction projects in the sample. Findings In contrast to prior literature in high-tech industries where exploitation focuses on continuous development, exploitation in construction projects often involves adopting conventional methods and solutions based on existing knowledge without any development efforts at all. This may enhance short-term efficiency and lower risk at the project level but increase risk at the firm level. Tight time schedules hinder both radical innovations and incremental developments, and the findings also reveal that to invest in efforts on explorative solutions, it must be possible to exploit the solutions in the same project. Research limitations/implications In this empirical context, the traditional structural and sequential ambidexterity solutions are not sufficient. In construction projects, contextual ambidexterity solutions in which key project actors collaborate in developing systemic innovations and fine-tuning solutions across projects are more effective. Practical implications Sufficient project size and/or long-term contracts over a series of projects enhance both investments in explorative activities and exploitation through continuous developments from project to project. In design–bid–build contracts, the client and consultant often miss opportunities to explore new technical solutions that rely on contractor competencies. Early procurement of contractors (e.g. in collaborative design–build contracts) thereby enables the achievement of both exploration and exploitation. Originality/value This study provides important input to the authors’ understanding of how exploration and exploitation may be managed in project-based industries, which has been scarcely studied in previous ambidexterity literature.
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Huo, Haohao, Yuzhen Li, Shaojie Wang, Siyang Tan, Xin Li, Siyuan Yi, and Lizhen Gao. "Construction of Highly Active Zn3In2S6 (110)/g-C3N4 System by Low Temperature Solvothermal for Efficient Degradation of Tetracycline under Visible Light." International Journal of Molecular Sciences 23, no. 21 (October 30, 2022): 13221. http://dx.doi.org/10.3390/ijms232113221.
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Herein, Zn3In2S6 photocatalyst with (110) exposed facet was prepared by low temperature solvothermal method. On this basis, a highly efficient binary Zn3In2S6/g-C3N4 was obtained by low temperature solvothermal method and applied to the degradation of tetracycline (TC). The samples of the preparation were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, UV–vis diffuse reflection spectroscopy, and photoluminescence spectroscopy. Furthermore, the degradation performance of photocatalysts on TC was investigated under different experimental conditions. Finally, the mechanism of Zn3In2S6/g-C3N4 composite material degrading TC is discussed. The results show that Zn3In2S6 and Zn3In2S6/g-C3N4 photocatalysts with excellent performance could be successfully prepared at lower temperature. The Zn3In2S6/g-C3N4 heterojunction photocatalyst could significantly improve the photocatalytic activity compared with g-C3N4. After 150 min of illumination, the efficiency of 80%Zn3In2S6/g-C3N4 to degrade TC was 1.35 times that of g-C3N4. The improvement of photocatalytic activity was due to the formation of Zn3In2S6/g-C3N4 heterojunction, which promoted the transfer of photogenerated electron–holes. The cycle experiment test confirmed that Zn3In2S6/g-C3N4 composite material had excellent stability. The free radical capture experiment showed that ·O2− was the primary active material. This study provides a new strategy for the preparation of photocatalysts with excellent performance at low temperature.
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An, Yuan, Jinji Ma, Yibo Gao, Wei Xiong, and Xianhua Wang. "Tomographic retrieval algorithm of OH concentration profiles using double spatial heterodyne spectrometers." Atmospheric Measurement Techniques 13, no. 12 (December 4, 2020): 6521–42. http://dx.doi.org/10.5194/amt-13-6521-2020.
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Abstract. The hydroxyl radical (OH) determines the capability of atmospheric self-cleansing and is one of the significant oxidants in atmospheric photochemistry reactions. Global OH has been monitored by satellites with the traditional limb mode in the past decades. This observed mode can achieve the acquisition of high-resolution vertical OH data but cannot obtain enough horizontal OH data for inverting high-precision OH concentrations because OH has a high reactivity that makes OH concentrations extremely low and distributions complicated. The double spatial heterodyne spectrometer (DSHS) is designed to obtain higher-resolution and more detailed OH data. This sensor can measure OH by the three-dimensional limb mode to obtain comprehensive OH data in the atmosphere. Here we propose a new tomographic retrieval algorithm based on the simulated observation data because the DSHS will work officially on the orbit in the future. We build up an accurate forward model. The main part of it is the SCIATRAN radiative transfer model which is modified according to the radiation transmission theory. The error in results obtained by the forward model is ±44.30 % in the lower atmosphere such as at a 21 km height and decreases gradually until the limit of observation altitude. We also construct the tomographic retrieval algorithm of which the core is a lookup table method. A tomographic-observation database is built up through the atmospheric model, the spatial information (the position of the target area and satellite position), the date parameters, the observation geometries, OH concentrations, and simulated observation data. The OH concentrations can be found from it directly. If there are no corresponding query conditions in the tomographic-observation database, the cubic spline interpolation is used to obtain the OH concentrations. The inversion results are given, and the errors in them increase as the altitudes rise until about a 41 km height then start to decrease. The errors in the inversion results reach the maximum of about ±25.03 % at the 41 km height and decrease to ±8.09 % at the limited observation height. They are also small in the lower atmosphere at ±12.96 % at 21 km. In summary, the tomographic retrieval algorithm can obtain more accurate OH concentrations even in the lower atmosphere where the OH data are not high quality and avoids the setting of initial guess values for solving the iteration problems. Our research not only provides support for the scientific theory of the construction of the DSHS but also gives a new retrieval algorithm idea for other radicals.
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Branchaud, Bruce P., and Mark S. Meier. "A novel strategy for the synthesis of ammonium 3-deoxy-D-manno-2-octulosonate (ammonium KDO) from lower monosaccharides. C-C bond construction of C6 of D-mannose via cobaloxime-mediated radical alkyl-alkenyl cross coupling." Journal of Organic Chemistry 54, no. 6 (March 1989): 1320–26. http://dx.doi.org/10.1021/jo00267a017.
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Stemrich, Raymond A., Neel Hasmukh Patel, Jacob A. Baber, and Mark J. Ferretti. "Robot-Assisted Nephroureterectomy for Upper Tract Urothelial Carcinoma in a Patient with an Ileal Conduit." Case Reports in Urology 2022 (May 4, 2022): 1–4. http://dx.doi.org/10.1155/2022/5321613.
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Background. Upper tract urothelial carcinoma remains an uncommon disease that is clinically difficult to identify early and surveil. Open nephroureterectomy is the gold standard for patients with high-grade disease, especially for patients in whom surveillance is complicated such as those with prior cystectomies/ileal conduits. This report presents a case of a patient with a history of radical cystectomy and ileal conduit construction who underwent a successful minimally invasive robotic surgery for treatment of upper tract urothelial carcinoma. Case Presentation. The patient is a 72-year-old Caucasian male with a history of recurrent superficial bladder tumors treated with cystoscopies with fulguration, Bacillus Calmette-Guerin, and a robot-assisted cystectomy with ileal conduit diversion presenting with recurrent urinary tract infections and hematuria secondary to a ureteral stricture. The patient was admitted previously for urosepsis during which time a percutaneous nephrostomy tube was inserted on the right side. Upon presentation, imaging revealed a lesion extending from the lower pole of the right kidney into the renal pelvis. The presence of a nephrostomy and urostomy allowed the surgical team to utilize a minimally invasive approach to remove the diseased kidney and ureter with visualization enhanced by indocyanine green. Conclusion. Minimally invasive robot-assisted approaches to treating upper tract urothelial carcinomas may offer an alternative to the open cases typically employed in cases of patients with prior ileal conduit. Furthermore, utilizing indocyanine green may expand the applicability of such approaches to uro-oncologic cases with greater complexity.
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Brock, Alice, Simon Kemp, and Ian D. Williams. "Personal Carbon Budgets: A Pestle Review." Sustainability 14, no. 15 (July 28, 2022): 9238. http://dx.doi.org/10.3390/su14159238.
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Personal Carbon Budgets (PCBs) are a radical policy innovation that seek to reduce an individual’s carbon consumption. This review identifies three archetypes of PCBs in the current literature; Personal Carbon Trading, Carbon Tax and Carbon Labelling. We theorised that carbon trading could affect equity and allow quality of life and consumption to be driven by income rather than needs. We, therefore, developed a new model (Personal Carbon Allowance with no trading) to compare to existing archetypes. A PESTLE (Political, Economic, Social, Technological, Legal, Environmental) framework was applied to each archetype to analyse and compare their costs and benefits and to critically evaluate and identify which model may be the most appropriate to reduce emissions severely but equitably. We conclude that the only model that can achieve this is our proposed Personal Carbon Allowance (PCA) model with no trading. PCA has a hard cap on emissions allowing for controllable severe cuts to emissions, and the lack of trading would prohibit those with wealth from continuing high-consumption lifestyles at the expense of those with lower incomes.
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Petr, Junga, Vondráčková Terezie, and Mareček Jan. "Conceptual design and evaluation of the alternative construction of lightweight hall building with polygonal ground plan and canvas roofing." Research in Agricultural Engineering 64, No. 1 (March 27, 2018): 20–25. http://dx.doi.org/10.17221/2/2017-rae.
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The paper presents the results of a conceptual study of lightweight wooden construction hall building with polygonal ground plan, suitable for agriculture. It comprises evaluation of chosen technical and functional characteristics and possibilities for animal production. The results of the study confirm advantages (mainly lower material and costs demandingness, environmentally friendliness, light-weight construction, fast assembly operations) and disadvantages (mainly larger range of groundwork, higher demandingness on roof structure, foundation of slab constructions and anchoring of vertical bearing constructions). Values of radial tensile stress at an interval of 9.0 to 21.0 MPa and tangential tensile stress at an interval of 1.4 to 16.0 MPa were calculated on vertical load 100 kN at the top of the construction). The construction makes possible to achieve a span as far as 60 m with effective canvas strain at large radius curvature from 80 m to 100 m.
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Houben, Georg J., Sarah Collins, Mark Bakker, Thomas Daffner, Falk Triller, and Anvar Kacimov. "Review: Horizontal, directionally drilled and radial collector wells." Hydrogeology Journal 30, no. 2 (January 8, 2022): 329–57. http://dx.doi.org/10.1007/s10040-021-02425-w.
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AbstractHorizontal wells play an often overlooked role in hydrogeology and aquifer remediation but can be an interesting option for many applications. This study reviews the constructional and hydraulic aspects that distinguish them from vertical wells. Flow patterns towards them are much more complicated than those for vertical wells, which makes their mathematical treatment more demanding. However, at some distance, the drawdown fields of both well types become practically identical, allowing simplified models to be used. Due to lower drawdowns, the yield of a horizontal well is usually higher than that of a vertical well, especially in thin aquifers of lower permeability, where they can replace several of the latter. The lower drawdown, which results in lower energy demand and slower ageing, and the centralized construction of horizontal wells can lead to lower operational costs, which can make them an economically feasible option.
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Faravelli, Tiziano, Alessio Frassoldati, Eliseo Ranzi, Miccio Francesco, and Miccio Michele. "Modeling Homogeneous Combustion in Bubbling Beds Burning Liquid Fuels." Journal of Energy Resources Technology 129, no. 1 (February 21, 2006): 33–41. http://dx.doi.org/10.1115/1.2424957.
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This paper introduces a model for the description of the homogeneous combustion of various fuels in fluidized bed combustors (FBC) at temperatures lower than the classical value for solid fuels, i.e., 850°C. The model construction is based on a key bubbling fluidized bed feature: A fuel-rich (endogenous) bubble is generated at the fuel injection point, travels inside the bed at constant pressure, and undergoes chemical conversion in the presence of mass transfer with the emulsion phase and of coalescence with air (exogenous) bubbles formed at the distributor and, possibly, with other endogenous bubbles. The model couples a fluid-dynamic submodel based on two-phase fluidization theory with a submodel of gas phase oxidation. To this end, the model development takes full advantage of a detailed chemical kinetic scheme, which includes both the low and high temperature mechanisms of hydrocarbon oxidation, and accounts for about 200 molecular and radical species involved in more than 5000 reactions. Simple hypotheses are made to set up and close mass balances for the various species as well as enthalpy balances in the bed. First, the conversion and oxidation of gaseous fuels (e.g., methane) were calculated as a test case for the model; then, n-dodecane was taken into consideration to give a simple representation of diesel fuel using a pure hydrocarbon. The model predictions qualitatively agree with some of the evidence from the experimental data reported in the literature. The fate of hydrocarbon species is extremely sensitive to temperature change and oxygen availability in the rising bubble. A preliminary model validation was attempted with results of experiments carried out on a prepilot, bubbling combustor fired by underbed injection of a diesel fuel. Specifically, the model results confirm that heat release both in the bed and in the freeboard is a function of bed temperature. At lower emulsion phase temperatures many combustible species leave the bed unburned, while post-combustion occurs after the bed and freeboard temperature considerably increases. This is a well-recognized undesirable feature from the viewpoint of practical application and emission control.
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Sakhno, Serhiy, Lyudmyla Yanova, Olena Pischikova, and Serhii Chukharev. "Study of the influence of properties of dusty ferromagnetic additives on the increase of cement activity." E3S Web of Conferences 166 (2020): 06002. http://dx.doi.org/10.1051/e3sconf/202016606002.
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Sustainable development of construction materials is directly related to research on the processes of hydration of binders. Builders need better types of cement, with lower cost and energy consumption in production. The development of spin chemistry methods allows us to consider the processes of hydration and structure formation of binders from the spin state of the elements involved in chemical reactions. Magnetic interactions have a significant effect on the spin dynamics and the control of the spin multiplicity of radical pairs. The practical implementation of magnetic effects on a binder can be carried out in various ways. However, a long-term impact can be achieved only by introducing ferromagnetic substances into the binders. In the paper presented the results of a study of the influence of the characteristics of finely dispersed powdered ferromagnetic additives on the strength characteristics of cement. Ferromagnetic additives regulate the behavior of the reactants during rotation during the hydration of the binders due to magnetic interactions and control the reactivity of the chemical reaction. A comparative analysis revealed that it is most expedient to use as powdery ferromagnetic additives are the waste from mining and processing enterprises of the Krivorozhsky field. The work investigated the magnetic and dispersed characteristics of 12 different dust. The experiments showed that the origin of dust and the method of their capture are determined their magnetic characteristics. Preparation of samples with the dust and determination of the strength characteristics of cement were carried out by standard methods. The results obtained made it possible to reveal the laws of the effect of the dispersed and magnetic properties of various dust on the degree of activation of binders.
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Tomšić, Željko, and Ivan Rajšl. "Electricity Market and Energy Policies Uncertainties for Investment in Life Time Operation of Nuclear Power Plants." Journal of Energy - Energija 68, no. 2-3 (July 8, 2022): 3–18. http://dx.doi.org/10.37798/2019682-3187.
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In the electricity sector, market participants must make decisions about capacity choice in a situation of radical uncertainty about future market conditions. Electricity sector is characterized by non-storability and periodic and stochastic demand fluctuations. Capacity determination is a decision for the long term, whereas production is adjusted in the short run. Today decisions pertaining to investment in new capacity or life time extension are surrounded by considerable uncertainties about the future economics of the projects. One reason is that in a deregulated market private investors typically have to bear a greater portion of the investment risk compared to a monopoly utility in a regulated market. This favours flexible investment alternatives with short-lead times and low capital requirements. Moreover, energy and climate policy – with feed-in tariffs for RES or green certificate system and the EU CO2 ETS may add to investment uncertainties. From the economic point of view, the costs of LTO are usually lower than the construction of any other source of electricity. But in the aftermath of the Fukushima accident, policies towards nuclear energy in some countries were changed. Because of that economic life decisions are plant specific. In evaluating the future economic prospects of existing plant, the owners/utility focus on the unique circumstances of that plant and its cost and performance, and the future demand for electricity, and value of electricity. Nevertheless, quantification of the LTO costs is not an easy task. It is recognized that LTO costs are highly dependent on specific conditions related to each NPP, such as: design of the plant; NPP operating history including ageing conditions; regulatory requirements; full or partial replacement of components; refurbishment for LTO; accounting methodologies; etc. The risks that may have an impact on the economic case for the long term operation of NPP should be identified with pre mitigation impact and probability assessment.
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Kabe, K., and T. Morikawa. "A New Tire Construction Which Reduces Ply Steer." Tire Science and Technology 19, no. 1 (January 1, 1991): 37–65. http://dx.doi.org/10.2346/1.2141707.
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Abstract Currently, the main tire construction is the radial construction. The radial construction consists of a carcass layer with cords parallel to the tire cross section and a belt layer which surrounds the tire in the circumferential direction and stiffens the tread band. The radial construction has better performance characteristics than the bias construction. It has higher durability, better wear resistance of the tread, lower rolling resistance, and better performance at high speed because of the stable contact response developed by the belt ply. On the other hand, the belt construction of the radial tire causes ply steer. This ply steer is also a cause of steering pull and uneven tread wear. This paper describes a new tire construction which enables the reduction of ply steer. The new construction features the carcass cord having some angle with respect to the tire cross section and also with respect to the cord of the adjacent belt ply. It is shown that the new tire construction can significantly reduce ply steer through variation of the carcass cord angle.
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Bauer, Rudolf F. "Equilibrium Profile of Modern Belted Radial Ply Tires: Its Determination and Performance Benefits." Tire Science and Technology 41, no. 2 (April 1, 2013): 127–51. http://dx.doi.org/10.2346/tire.13.410203.
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ABSTRACT The benefits of a tire's equilibrium profile have been suggested by several authors in the published literature, and mathematical procedures were developed that represented well the behavior of bias ply tires. However, for modern belted radial ply tires, and particularly those with a lower aspect ratio, the tire constructions are much more complicated and pose new problems for a mathematical analysis. Solutions to these problems are presented in this paper, and for a modern radial touring tire the equilibrium profile was calculated together with the mold profile to produce such tires. Some construction modifications were then applied to these tires to render their profiles “nonequilibrium.” Finite element methods were used to analyze for stress concentrations and deformations within all tires that did or did not conform to equilibrium profiles. Finally, tires were built and tested to verify the predictions of these analyses. From the analysis of internal stresses and deformations on inflation and loading and from the actual tire tests, the superior durability of tires with an equilibrium profile was established, and hence it is concluded that an equilibrium profile is a beneficial property of modern belted radial ply tires.
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Liu, Mingliang, Junhai Zhao, Yongkang Jiao, Cun Hui, Chunjuan Zhou, Xiao Yang, and Yupeng Zhang. "Study on Construction Molding Technology of Long-Span Space Truss Suspended Dome Structure." Metals 13, no. 1 (December 22, 2022): 22. http://dx.doi.org/10.3390/met13010022.
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Typically, the upper part of the roof a gymnasium building is a radial inverted triangular truss structure, and the lower part is a cable structure. They are connected by vertical braces to form a self-balancing structural system. The whole roof is supported by a complex, spatial, prestressed structure comprising tilted Y-shaped laced columns. Such structures rely on the integrity of the form and the application of prestress to achieve the best performance; it is in an extremely unstable state during construction. In order to study the mechanical behavior of the structure in this process, finite element software was used to analyze the cumulative slip of the structure and the construction process of cable tension, and the simulation values were compared to the actual monitoring values. The stress and deformation of the structure in different construction stages were investigated, and a reasonable structural unloading scheme was put forward. The study results showed that the stiffness of the long-span space truss suspended dome structure gradually increased with the structural integrity during construction, and the vertical deformation decreased from 25.4 mm to 19.26 mm with the construction process. The location and magnitude of the structure’s maximum internal force and maximum stress varied greatly compared to the static analysis when considering the construction process effects. Hence, conducting a construction process analysis is necessary. The construction technology of symmetrical rotating cumulative slip proposed in this paper has the advantages of a short construction duration, safe and stable construction process, etc., providing technical references for similar engineering constructions.
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Lee, Emerson, Tanmay Singh, Misop Han, Curtiland Deville, Aditya Halthore, Stephen C. Greco, Phuoc T. Tran, Theodore L. DeWeese, and Danny Song. "Early initiation of salvage radiotherapy is associated with improved metastasis-free survival in patients with relapsed prostate cancer following prostatectomy." Journal of Clinical Oncology 40, no. 6_suppl (February 20, 2022): 262. http://dx.doi.org/10.1200/jco.2022.40.6_suppl.262.
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262 Background: Salvage radiation therapy is a recognized management option for patients who develop biochemical failure following radical prostatectomy. However, given the documented long natural history of biochemically relapsed prostate cancer after prostatectomy, questions remain on the value of early salvage intervention vs initial expectant management, especially with regards to more critical clinical rather than biochemical endpoints. We sought to determine the impact of early salvage radiotherapy (initiated at PSA 0.2 - 0.5 ng/ml) on metastasis-free survival in patients who receive salvage radiotherapy following prostatectomy for clinically localized prostate cancer. Methods: Using tumor registry data, we identified 408 patients who received salvage radiation therapy between 1986 – 2016 at our institution. We analyzed association between survival outcomes and prognostic factors, including pre-treatment and nadir prostate-specific antigen (PSA), interval between prostatectomy and initiation of salvage RT, use of neoadjuvant/concurrent hormonal suppression, and adverse pathologic features, including Gleason score, extraprostatic extension, seminal vesicle invasion, nodal involvement, and margin status. Univariate analyses and multivariable-adjusted Cox proportional hazards models were constructed to assess association between these clinical and pathologic features and duration of biochemical relapse-free survival (bRFS) and metastasis-free survival (MFS). Construction of Kaplan-Meier survival curves stratifies survival by predictive features. Results: Overall, 187 (45.8%) patients received salvage radiotherapy while PSA levels were 0.2 - 0.5 ng/ml (early salvage). One hundred thirty three (32.6%) patients received neoadjuvant/concurrent androgen deprivation therapy (ADT). Median radiation dose was 68.4 Gy and did not differ significantly between treatment subgroups. Independent of pathologic features and use of ADT, early-salvage at lower PSA levels was the most significant predictor of improved bRFS and MFS, HR = 0.52 (95% CI [0.35, 0.79], p = 0.002), and HR = 0.58 (95% CI [0.37, 0.91], p = 0.02), respectively. Seminal vesicle invasion was associated with shorter interval to biochemical failure (HR = 1.79 (95% CI [1.07, 2.98], p = 0.03), but not significant difference in MFS. Conversely, nodal involvement was a significant predictor of worse MFS, with HR = 2.18 (95% CI [1.04, 4.57], p = 0.04). Notably, interval between prostatectomy and initiation of salvage radiation was not a significant prognostic factor for bRFS or MFS. Conclusions: Independent of pathologic features and use of ADT, the initiation of salvage radiation therapy early after biochemical relapse (PSA ≤ 0.5 ng/ml) following prostatectomy is associated with increased metastasis-free as well as biochemical relapse-free survival.
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Yang, Zhiyong, Yaowen Ding, Yusheng Jiang, Kuanda Fang, Linwei Dong, Weiqiang Qi, and Zheng Wei. "Study of the Construction Sequence of Overlapping Tunnels by the Shield Tunneling Method: A Case Study of the Longest Overlapping Tunnel in China." Advances in Civil Engineering 2020 (August 12, 2020): 1–9. http://dx.doi.org/10.1155/2020/4909750.
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In this study, the reasonable construction sequence of an overlapping tunnel shield is investigated. Taking the overlapping tunnel of Tianjin Metro Line 5 as the background, a three-dimensional numerical model was established using Flac3D software to study the influence of the “first up and then down” and “first down and then up” construction sequences of the overlapping tunnel on the surface settlement, stratum displacement, lining radial stress, and displacement. The research results show that the shape and width of the final settlement tank on the ground under the two conditions are basically the same, and the difference between the maximum cumulative settlements is small. The accumulated ground settlement caused by the first up and then down construction sequence is 1.8 mm larger than that caused by the first down and then up sequence. The difference between the two working conditions on the vertical displacement of the stratum mainly occurs in the middle stratum of the upper and lower tunnels, and the proportion of the strata in the uplifted state and subsidence state is different. The construction sequence has little effect on the radial stress on the lining of the upper and lower tunnels. Under these two conditions, the excavation of the second tunnel causes a small change in the radial stress of the preceding tunnel lining, both within 4.2%. Under the working condition of first down and then up, the construction of the second tunnel causes the lining of the preceding tunnel to rise by 7.2∼9.2 mm. Under the condition of first up and then down, the construction of the second tunnel causes the lining of the preceding tunnel to sink again by 9.1∼10.4 mm. By comparing the effects of the two working conditions on the stratum and the tunnel lining, it is recommended that the construction be carried out in the order of first down and then up.
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Hayrapetyan, Yegisabet Hakob, and Stepan Karen Petrosyan. "Construction Features of The High-Precision Laser Rangefinder Light Modulator." Journal of Architectural and Engineering Research 1, no. 1 (June 25, 2021): 26–31. http://dx.doi.org/10.54338/27382656-2021.1-5.
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The issues related to the development of a light modulator operating on the electro-optical effect of laser rangefinders by the modulation method are considered. To reduce the modulation power, it is proposed to lower the modulation frequency to 750-800 MHz, while simultaneously increasing the modulation quality to Q = 1000. The study of the phase determination error of a high-precision laser rangefinder depending on temperature showed that it is rational to construct the light modulator by radial installation of the KDP electro-optical crystal, with separated modulation and demodulation channels, while on combined resonators.
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Twarock, Reidun, Motiejus Valiunas, and Emilio Zappa. "Orbits of crystallographic embedding of non-crystallographic groups and applications to virology." Acta Crystallographica Section A Foundations and Advances 71, no. 6 (September 22, 2015): 569–82. http://dx.doi.org/10.1107/s2053273315015326.
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The architecture of infinite structures with non-crystallographic symmetries can be modelledviaaperiodic tilings, but a systematic construction method for finite structures with non-crystallographic symmetry at different radial levels is still lacking. This paper presents a group theoretical method for the construction of finite nested point sets with non-crystallographic symmetry. Akin to the construction of quasicrystals, a non-crystallographic groupGis embedded into the point group {\cal P} of a higher-dimensional lattice and the chains of allG-containing subgroups are constructed. The orbits of lattice points under such subgroups are determined, and it is shown that their projection into a lower-dimensionalG-invariant subspace consists of nested point sets withG-symmetry at each radial level. The number of different radial levels is bounded by the index ofGin the subgroup of {\cal P}. In the case of icosahedral symmetry, all subgroup chains are determined explicitly and it is illustrated that these point sets in projection provide blueprints that approximate the organization of simple viral capsids, encoding information on the structural organization of capsid proteins and the genomic material collectively, based on two case studies. Contrary to the affine extensions previously introduced, these orbits endow virus architecture with an underlying finite group structure, which lends itself better to the modelling of dynamic properties than its infinite-dimensional counterpart.
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Blikharskyy, Yaroslav. "Calculation of damage RC constructions according to deformation model." Theory and Building Practice 2020, no. 2 (November 20, 2020): 99–106. http://dx.doi.org/10.23939/jtbp2020.02.099.
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This article presents results of a theoretical study of reinforced concrete beams with damaged reinforcement. The change of micro-hardness of a reinforcing rebar’s with a diameter of 20 mm of A500C steel in the radial direction is investigated and the thickness of the heat-strengthened layer is established. It is established that the thickness of the thermo-strengthened steel layer of the reinforcing bar with a diameter of 20 mm of A500C is approximately 3 mm. It is shown that the strength characteristics of this layer are on 50% higher compared to the core material of the rebar, while the plasticity characteristics are lower. The aim of the work is to determine the strength and deformability of reinforced concrete structures without damaging the reinforcement and in case of damage. Determining the impact of changes in the physical characteristics of reinforcement on the damage of reinforced concrete structures, according to the calculation to the valid norms, in accordance with the deformation model. To achieve the goal of the work, theoretical calculations of reinforced concrete beams were performed according to the deformation model, according to valid norms. This technique uses nonlinear strain diagrams of concrete and rebar and is based on an iterative method. According to the research program 3 beam samples were calculated. Among them were undamaged control sample with single load bearing reinforcement of ∅20 mm diameter – BC-1; sample with ∅20 mm reinforcement with damages about 40% without changes in the physical and mechanical properties of reinforcement – BD-2 and sample with ∅20 mm reinforcement with damages about 40% with changes in the physical and mechanical properties of reinforcement – BD-3. The influence of change of physical and mechanical characteristics of rebar’s on bearing capacity of the damaged reinforced concrete beams is established.
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Haude, R. "Origin of the holothurians (Echinodermata) derived by constructional morphology." Fossil Record 5, no. 1 (January 1, 2002): 141–53. http://dx.doi.org/10.5194/fr-5-141-2002.
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According to a recent hypothesis, the holothurians originated by a process of extreme paedomorphism as "giant larvae", with "<i>de novo</i>" developed radial systems. However, the present approach, which follows the principles of constructional morphology, supports former views that the holothurian predecessor must have been echinoid-like. After constitution of a (reliable) early predecessor construction as a model with machine analogies, subsequent steps of structural transformation are explained by functional improvement and economy. Following results are discussed: (i) Holothurians have to be derived from a postlarval precursor; (ii) "Apodida" (as molecular-genetically derived first holothurians) must originally have been pedate; (iii) ophiocistioids would not be cladistic “holothurians” but a precursor construction of the taxon echinoids plus holothurians; (iv) the Lovenian structure of the calcareous ring of <i>Nudicorona</i> (Middle Devonian), possible radial series in <i>Palaeocucumaria</i> (Lower Devonian), and distribution of the podia in two new holothurian body fossils from the Lower and Middle Devonian (preliminary description as <i>Prokrustia tabulifera</i> n. gen., n. sp. and <i>Podolepithuria walliseri</i> n. gen., n. sp.) obviously corroborate homology of holothurian and other echinoderm radial systems; (v) different extent of podial and body wall skeletonization suggests the existence of respiratory trees by no later than the Middle Devonian. <br><br> Nach einer neueren Erklärung, die sich auf eine Theorie zur Homologisierung von larvalen und adulten Strukturen von Echinodermen stützt, sollen die Holothurien über extreme Paedomorphose, d.h. über „Riesen-Larven” mit neugebildeten postoralen Radial-Systemen entstanden sein. Dagegen läßt sich anhand eines konstruktions-morphologischen Verfahrens zeigen, daß Holothurien auf einen Echiniden-artigen Vorläufer zurückzuführen sind. So wird zunächst eine (wahrscheinliche) frühe Vorläufer-Konstruktion der Echinozoen nach Maschinen-Analogien konstituiert. Die daran anschließenden strukturellen Transformationen werden nach funktionellen und energetischen Kriterien begründet. Sie führen zwanglos zu Konstruktionen, die nicht nur rezenten Formen entsprechen, sondern offensichtlich auch durch bekannte und neue paläozoische Fossilien bestätigt werden. Im Einzelnen werden folgende Ergebnisse zur Diskussion gestellt: (i) Holothurien sind von einer post-larvalen Vorläufer-Konstruktion abzuleiten; (ii) die füßchenlosen „Apodida” (als molekulargenetisch früheste Holothurien) müssen zunächst vollständige Radien mit Podia besessen haben; (iii) bei den (nur paläozoischen) Ophiocistioiden handelt es sich nicht kladistisch um „Holothurien”, sondern sie repräsentieren eine Vorläufer-Konstruktion des Taxon Echiniden plus Holothurien; (iv) die Loven'sche Struktur des Schlundrings von <i>Nudicorona</i> (Mittel-Devon), die möglicherweise radialen Strukturen bei <i>Palaeocucumaria</i> (Unter-Devon) und die Verteilung der Podia in zwei neuen, vollständig erhaltenen Holothurien aus dem Unter- und Mittel-Devon (vorläufige Beschreibung als <i>Prokrustia tabulifera</i> n. gen., n. sp. und <i>Podolepithuria walliseri</i> n. gen., n. sp.) stützen die konstruktions-morphologische Begründung der Homologie der Radial-Systeme bei Holothurien und den übrigen Echinodermen; (v) das deutlich unterschiedliche Ausmaß der Skelettierung von Podia bei den neuen Holothurien-Funden scheint anzudeuten, daß die analen Respirations-Strukturen der Holothurien spätestens ab dem Mittel-Devon vorhanden sind. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.20020050110" target="_blank">10.1002/mmng.20020050110</a>
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Saraswati, Saraswati, Yubraj Bhusal, Andrew J. Trant, and Maria Strack. "Roads Impact Tree and Shrub Productivity in Adjacent Boreal Peatlands." Forests 11, no. 5 (May 24, 2020): 594. http://dx.doi.org/10.3390/f11050594.
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Peatlands in the western boreal plains of Canada are important ecosystems as they store over two percent of global terrestrial carbon. However, in recent decades, many of these peatlands have been fragmented by access roads constructed for resource extraction and transportation, challenging their carbon storage potential. To investigate how roads have been impacting tree and shrub growth and productivity in these peatlands, this study was conducted in a forested bog and woody fen in Carmon Creek, Alberta, Canada. In 2017, vegetation surveys were conducted along 20 m transects that extended on both sides of the road with 4 m2 circular plots at 2, 6 and 20 m distance from the road and were followed by disc or core collection from woody stems. Within 20 m of the road at the bog site, we observed a shift towards significantly larger radial growth of trees in the downstream areas (t = 3.23, p = 0.006) where water table position was deeper, while at the fen site, radial growth of tall shrubs had little response to the road. Combining the effects of direct tree clearing and hydrology induced shifts in growth, aboveground net primary productivity (NPPag) post-road construction was reduced significantly in areas where vegetation was cleared during the road construction (i.e., upstream areas of the bog: t = 5.21, p < 0.0001 and downstream areas of the fen: t = 2.64, p = 0.07). Substantially lower NPPag around the road construction areas compared to reference areas shows tremendous loss of carbon sink potential of trees and shrubs after road construction through peatlands. Altogether, roads constructed through peatlands perpendicular to the water flow may shift long-term carbon sinks into sources of carbon, at least for the initial few years following road construction.
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Larsson, Martin, and Johanna Nešlehová. "Extremal behavior of Archimedean copulas." Advances in Applied Probability 43, no. 1 (March 2011): 195–216. http://dx.doi.org/10.1239/aap/1300198519.
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We show how the extremal behavior of d-variate Archimedean copulas can be deduced from their stochastic representation as the survival dependence structure of an ℓ1-symmetric distribution (see McNeil and Nešlehová (2009)). We show that the extremal behavior of the radial part of the representation is determined by its Williamson d-transform. This leads in turn to simple proofs and extensions of recent results characterizing the domain of attraction of Archimedean copulas, their upper and lower tail-dependence indices, as well as their associated threshold copulas. We outline some of the practical implications of their results for the construction of Archimedean models with specific tail behavior and give counterexamples of Archimedean copulas whose coefficient of lower tail dependence does not exist.
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Larsson, Martin, and Johanna Nešlehová. "Extremal behavior of Archimedean copulas." Advances in Applied Probability 43, no. 01 (March 2011): 195–216. http://dx.doi.org/10.1017/s0001867800004754.
Full textAbstract:
We show how the extremal behavior of d-variate Archimedean copulas can be deduced from their stochastic representation as the survival dependence structure of an ℓ1-symmetric distribution (see McNeil and Nešlehová (2009)). We show that the extremal behavior of the radial part of the representation is determined by its Williamson d-transform. This leads in turn to simple proofs and extensions of recent results characterizing the domain of attraction of Archimedean copulas, their upper and lower tail-dependence indices, as well as their associated threshold copulas. We outline some of the practical implications of their results for the construction of Archimedean models with specific tail behavior and give counterexamples of Archimedean copulas whose coefficient of lower tail dependence does not exist.
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Antas, Stanisław. "Exhaust System for Radial and Axial-Centrifugal Compressor with Pipe Diffuser." International Journal of Turbo & Jet-Engines 36, no. 3 (August 27, 2019): 297–304. http://dx.doi.org/10.1515/tjj-2016-0068.
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Abstract The application of radial and axial-centrifugal compressors in turboprop, turboshaft and turbofan engines may require the construction of small diameters diffuser in order to obtain lower weight and smaller frontal area. Conventional exhaust diffusers typically have large outlet diameters for exit Mach numbers lower than 0,2 and low swirl flow to the combustor, hence the design of channel of the low-diameter diffusers called controlled-contour, fishtail-shaped diffuser or diffusing trumpet is complex. The cross-sectional shape of these channels is varied from circular to oval to elliptic and to rectangular. The paper presents an original method for determining the flow parameters in the channel and at the outlet section of the downstream diffusing trumpet for a pipe diffuser, which constitutes the downstream duct of the radial or axial-centrifugal compressor with the pipe diffuser. It also illustrates a new method for determining the geometrical parameters of the diffuser. Mentioned methods (for conceptual design of a compressor with pipe diffuser) are based on Pythagorean theorem, properties of ellipse, equation of continuity, energy equation, first law of thermodynamics, Euler’s moment of momentum equation, gasdynamics functions and definitions used in theory of turbo-machines.
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Lenevych, Oksana, and Zinoviy Pankiv. "LANDUSE FEATURES IN A MOUNTAIN AREA AND THEIR EFFECTS ON THE PROCESS OF SYLVATISATION (STRYY DISTRICT LVIV REGION)." PROBLEMS OF GEOMORPHOLOGY AND PALEOGEOGRAPHY OF THE UKRANIAN CARPATHIANS AND ADJACENT AREAS, no. 14 (December 30, 2022): 189–202. http://dx.doi.org/10.30970/gpc.2022.1.3861.
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The Skole District that is nowadays a part of newly established Stryy District (Lviv Region) is entirely situated within the range of the Ukrainian Carpathians. Its area encompasses the Skolivsli Beskydy and the Stryy-San Highland physiographic regions featuring a dominance of considerably high altitudes above sea level, terrain disarticulation, and afforestation. Establishing new villages alongside rural population’s natural increase and land reforms (the capitalist stage of land use (after the abolition of serfdom in 1848) and Soviet stage of land use) called for respective increase in agricultural lands. Forested lands in the Ukrainian Carpathians were the source for such an increase therefore cropland and pasture lands were emerging from deforestation. Harsh weather conditions and low soil fertility significantly impacted the further agricultural land uses in the mountainous region. However, wide-scale decline of agricultural lands occurred in the period of the collapse of the former USSR due to decline of collective and state farms. As a result of denationalization with subsequent privatization of agricultural lands there are nowadays 31 303 land owners and land users in the study area, 97,54 % of which are physical persons. At the same time, despite such remarkable figures citizens share less than a half of total lands for agriculture, residential and construction purposes, whilst the state forestry enterprises are using 51,11 % (75 173,50 ha) in total. In contrast to lowlands, animal farming and husbandry in the Skole District is held exclusively by households. In recent years local animal husbandry is experiencing the livestock decline that leads to certain reduction in the share of both hay meadows and pasturelands. Thus, from 2009 to 2016 the total area of fodder lands in the district decreased by 65 ha (ca. 0,2 % of total privately owned agricultural lands). I assume that ongoing land reform will cause further increase in fallows in the Skole District. In order to better comprehend the processes of spontaneous reforestation (sylvatisation) in a mountain region (the Pohartsi boundary, Koziova village, Stryi district, Lviv regionthe ) four study plots were selected representing the successional sequence: forest → pasture → hay meadow → arable lands. The study showed that areas that were previously used for pasture and were not plowed, are restored to their natural state much faster. These areas are characterized by satisfactory physical, physico-chemical and biotic properties. The decrease in acidity towards the neutral side is explained by an increase in the activity of catalase and urease by approximately 1.5 times. In connection with the developed grass cover, slightly higher nitrogen values were recorded in the upper soil horizon. Due to the absence of a regular annual supply to the base and replenishment of its nutrient reserves due to precipitation and waste of dead phytomass, the content of humus in the upper horizon of the base is half as much as under forest biogeocenoses. Plowing (overturning the lower horizons to the mountain, and vice versa) is a very strong anthropogenic factor, which leads to the almost complete destruction of natural vegetation on the cultivated area and a radical change in the main properties of the soil cover. According to some indicators: physical (total sparability), physico-chemical (nitrogen nitrate and ammonia), biotic (urease, catalase, biomass of microorganisms) in the upper humus horizons were even somewhat close to anthropogenically unaltered ecosystems. However, the changes in the indicators of the density of the soil structure and its solid phase corresponded to the depth of plowing. And the humus content was several times lower than under forest biogeocenoses. Areas that were not plowed in the past are restored due to the main rock of the region Picea abies (L.) Karst.. Areas that were devastated in the past are recovering much more slowly. Such areas begin to overgrow with Alnus incana (L.) Moench., Rosa canina L., Bеtula and others Key words: land use; land owners and land users; fallows; agricultural lands; mountainous region; Skolivski Beskydy.
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Maistruk, Volodymyr. "Study of the structure of gas flow іn a cyclone wіth іntermedіate dust removal." Bulletin of the National Technical University «KhPI» Series: New solutions in modern technologies, no. 3(9) (October 18, 2021): 48–54. http://dx.doi.org/10.20998/2413-4295.2021.03.07.
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The works in which designs of the dust collectors, which are often used in the industry, are analyzed. It is shown that the efficiency of dust collectors largely depends on the structure of the gas flow in the apparatus. Based on the analysis of the current cyclone devices, a picture of the separation process is obtained, and the factors that negatively affect the operation of dust collectors are identified. It is established that forecasting the work of dust collecting devices in certain conditions is most effective to perform methods of numerical modeling and simulation of the separation process, which are widely used for the research of devices of this type. Using the methods of numerical simulation, the study of the cyclone with intermediate dust removal was carried out. In this cyclone, the change in the radius of the apparatus of the tangential, radial, and axial velocity components is investigated. In the course of the research, it is established that in the separation space the tangential component of velocity increases from 18–20 m/s in the upper part of the device to 22–25 m/s in the area of the lower end of the exhaust pipe, the radial component of velocity takes values from 0 to 2 m/s, and the axial component of the speed has a maximum value of 10–15 m/s. In the conical part of the apparatus the tangential component of velocity decreases from 27 m/s in the upper planes of the conical part of the apparatus to 10 m / s near the dust unloading pipe, the radial component of speed has centripetal character, the axial component of speed decreases as the gas flow to the dust unloading pipe decreases. It has been established that in the cylindrical part of the apparatus about 60 % of the gas flow volume is transferred from the downstream to the upstream by a secondary vortex, and in the conical part, about 40 % of the gas volume is transferred from the downstream to the upstream. It is shown that large values of the tangential component of velocity in the separation zone contribute to the ingress of dust particles into the annular space behind the dust unloading holes, and small values of the tangential component of velocity, axial and radial in the annular space behind the dust unloading holes has a positive effect on the operation of the dust collector.
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Bakht, Baidar, and Akhilesh C. Agarwal. "On distress in pipe-arches." Canadian Journal of Civil Engineering 15, no. 4 (August 1, 1988): 589–95. http://dx.doi.org/10.1139/l88-079.
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Cracking of bolt holes is a very common form of distress in pipe-arch type of soil–steel structures, the conduit walls of which are subjected to very large radial soil pressures in their lower haunches. This paper, in discussing the mechanics of this form of distress, concludes that the cracks are formed mainly due to the inability of the soil in the haunch areas to sustain the very high pressures. It also contains methods to alleviate these problems, both at the design and at the construction stage. Guidelines for proper bolt arrangements are given, and use of low-strength concrete around and under the haunches is recommended. Pouring of concrete in segments is suggested to avoid potential flotation of the pipe during construction. A case history incorporating this measure is given to demonstrate its feasibility. Key words: soil–steel structure, pipe-arch, culvert, highway bridges, bolt-hole tears.
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Dawson, Andrew R., and Simon D. Gillett. "Assessment of On-Sample Instrumentation for Repeated Load Triaxial Tests." Transportation Research Record: Journal of the Transportation Research Board 1614, no. 1 (January 1998): 52–60. http://dx.doi.org/10.3141/1614-07.
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Five laboratories have been involved in a series of comparative studies of the repeated load triaxial testing of soils and unbound granular materials as found in the lower layers of pavement construction. These comparisons with soil, granular materials, and an artificial specimen are outlined. The performance of the varied types of instruments that measure both axial and radial deformations is assessed, with particular attention to the fixing arrangements, instrument limitations, and weight. On the basis of the information presented, recommendations are given about the most appropriate types of instrument. No universal type is recommended, and it is clear that some variation in performance is an inevitable consequence of the measurement process.
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Boris, Yaroslav, and Oleksij Teleguz. "PECULIARITIES OF THE URBAN SOILS OF THE CITY OF LVIV." SCIENTIFIC ISSUES OF TERNOPIL VOLODYMYR HNATIUK NATIONAL PEDAGOGICAL UNIVERSITY. SERIES: GEOGRAPHY 52, no. 1 (May 30, 2022): 59–65. http://dx.doi.org/10.25128/2519-4577.22.1.8.
Full textAbstract:
The soil cover of the city of Lviv has been changed or has undergone radical modifications by the direct influence of human activities. The urban soils are the most common in the city, occupying about 2/3 of its territory. They change under the influence of vehicles, industry, construction and reconstruction processes and carry a constant load on the natural soils, causing changes in almost all their components: a morphological structure, from physical and chemical properties to microbiological and biochemical parameters, depriving the soils in the city of the ability to perform important environmental functions such as an effective absorption of industrial and automotive emissions, forming a new urban horizon and displacing the natural soils. The natural soils cover has been preserved only in small areas in city and forest parks and on the outskirts of the city.
The urban soils of the central area of the city on the territory of the lower front part of the Ivan Franko Park in Lviv have been studied. The study of the soil profiles of this area showed special features: the soil is completely loose, and the thickness of the profiles reaches two meters or more, consisting of an anthropogenic material; a significant number of artifacts in particular (ceramic ware and fragments of pots, glass, metal, leather, as well as numerous finds of ancient coins dating from the sixteenth - nineteenth centuries) have been found in the soil profiles. There are also buried horizons in the profiles of the urban soils, darker in color due to the accumulation of an organic material and a looser consistency, with a high content of the plant roots and the soil microorganisms. The studied soil profiles of this area have testified to the specificity of their features. The soils of this part of the city are completely loose with a lot of an anthropogenic material. If the natural forest soils within a complex green zone of the city are characterized by the high acidity (pH 4.5-4.9) and a lack of nutrients, the anthropogenically altered bulk soils are characterized by a neutral or alkaline reaction (pH 7.1-7.9) and, as a rule, enough nutrients. There is a high content of calcium carbonates due to the presence of inclusions of a lime plaster, which is caused by a slight alkaline reaction, low hydrolytic acidity and a high degree of the saturation of the bases. Different concentrations of humus in the horizons or its absence lead to the fact that the urban soils have many similar and individual features, and only with a small degree of probability can we assume what properties certain urban soils have. There is a significant tendency to contaminate the soil with heavy metals. It is difficult to clearly and unambiguously connect the features of the morphology of the urban soils of the city of Lviv with the functional zoning of a city. Therefore, the condition of the soils of the urban area requires constant monitoring by scientists and special attention because due to the growth of the urban environment almost all their components are changing.
Key words: urban soil, soil profile, urban soil, cultural layer, urban ecosystems.
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D’Alessio, Matteo, John Lucio, Ernest Williams, James Warner, Donald Seymour, Jay Jasperse, and Chittaranjan Ray. "Flow Analysis through Collector Well Laterals: A Case Study from Sonoma County Water Agency, California." Water 10, no. 12 (December 13, 2018): 1848. http://dx.doi.org/10.3390/w10121848.
Full textAbstract:
The Sonoma County Water Agency (SWCA) uses six radial collector wells along the Russian River west of Santa Rosa, to provide water for several municipalities and water districts in north-western California. Three collector wells (1, 2, and 6) are located in the Wohler area, and three collector wells (3, 4, and 5) are located in the Mirabel area. The objective of this paper is to highlight the performance of the three collector wells located in the Mirabel area since their construction. The 2015 investigation showed a lower performance of Collectors 3 and 4 compared to their original performances after construction in 1975, while the performance of Collector 5 was relatively stable since 1982. The potential change in capacity could be due to the increase in encrustation observed during the visual inspection of laterals in all three collector wells. Overall, the three collectors are still within the optimal design parameters (screen entrance velocity < 0.305 m min−1 and axial flow velocity of lateral screens < 1.524 m s−1).
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Madej, Jerzy, and Bartłomiej Będkowski. "AIR FLOW ANALYSIS FOR ELECTRICAL MOTOR'S COOLING SYSTEM WITH AUTODESK SIMULATION CFD 2013 PROGRAM." Acta Mechanica et Automatica 7, no. 2 (June 1, 2013): 89–92. http://dx.doi.org/10.2478/ama-2013-0016.
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Abstract In the article the analysis of airflow through electrical motor was conducted and optimal design solution was chosen in order to increase cooling efficiency. Numerical simulations allow to determine the areas of temperature occurrence which may have destructive influence on electrical motor parts and on its safe operation. The numerical calculations of airflow was carried out for two different types of fans as well as for two different housings. An analysis of the construction was carried out by CFD method using Autodesk Simulation CFD 2013. Community results of the analysis, we can conclude that the better solution for machines with fixed direction of rotation is to use instead of the radial the axial fan. For axial fan the motor temperature in the same condition was lower by about 5°C.
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Estevez-Delgado, Gabino, and Joaquin Estevez-Delgado. "Compact stars." Modern Physics Letters A 33, no. 15 (May 20, 2018): 1850081. http://dx.doi.org/10.1142/s0217732318500815.
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An analysis and construction is presented for a stellar model characterized by two parameters (w, n) associated with the compactness ratio and anisotropy, respectively. The reliability range for the parameter w [Formula: see text] 1.97981225149 corresponds with a compactness ratio u [Formula: see text] 0.2644959374, the density and pressures are positive, regular and monotonic decrescent functions, the radial and tangential speed of sound are lower than the light speed, moreover, than the plausible stability. The behavior of the speeds of sound are determinate for the anisotropy parameter n, admitting a subinterval where the speeds are monotonic crescent functions and other where we have monotonic decrescent functions for the same speeds, both cases describing a compact object that is also potentially stable. In the bigger value for the observational mass M = 2.05 M[Formula: see text] and radii R = 12.957 Km for the star PSR J0348+0432, the model indicates that the maximum central density [Formula: see text] = 1.283820319 × 10[Formula: see text] Kg/m3 corresponds to the maximum value of the anisotropy parameter and the radial and tangential speed of the sound are monotonic decrescent functions.
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Al-Dulaimi, M. J., F. A. Hamad, A. A. Abdul Rasool, and K. A. Ameen. "Effect of sand particles on flow structure of free jet from a nozzle." Journal of Mechanical Engineering and Sciences 13, no. 3 (September 27, 2019): 5542–61. http://dx.doi.org/10.15282/jmes.13.3.2019.21.0447.
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The Characteristics of single and two- phase flow from a circular turbulent free jet from a nozzle of 10 mm diameter were investigated experimentally and numerically. The measurements were conducted for ReJ = 10007 - 31561. The velocity was measured at location from the nozzle y/D (0-8) in axial and radial directions. The two phase measurement were done by using natural construction sand as a solid phase of sizes (220,350,550) µm and loading ratios (mass flow ratio of sand to mass flow rate of air) in the range (0.18-1.38). Two phase air velocity of jet showed that the introducing of natural sand particles gives lower jet velocity attributed to momentum transfer to particles. The smaller particle size leads to lower values of velocity. The velocity found to be decreased with loading ratio increase. The numerical simulation was performed for single and two phase jet flow. RNG K-ε turbulence model was used to simulate the flow of fluid and the discrete phase model to simulate the particles flow. The results form numerical simulation showed a good agreement with experimental results.