Journal articles on the topic 'Systems and components (SSCs)'
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1
Kang, Mi-Yeon, Yeheun Jeong, and Youngsoo Jung. "Assessment Methodology of Practical Configuration Management (CM) for Sustainable Nuclear Power Plants (NPPs)." Sustainability 11, no. 8 (April 22, 2019): 2391. http://dx.doi.org/10.3390/su11082391.
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Since the Fukushima accident in 2011, nuclear safety has emerged as a very important political and social issue. Under this circumstance, the importance of configuration management (CM) is emphasized in order to ensure the reliability and safety of facility. However, configuration management (CM) is still in its conceptual stage in the nuclear industry due to the ambiguity of CM definitions, insufficiency of CM procedures, paucity of computerized systems and lack of CM professionals. In an attempt to address this issue, a previous study proposed a comprehensive CM framework for nuclear power plants (NPPs) by comparing CM concepts in seven different industries where the CM is actively utilized. In order to facilitate the practical implementation of the conceptual framework, this paper proposes an assessment methodology for prioritizing the importance of CM application areas based on the physical subjects of NPP structures, systems, components (SSCs). The proposed methodology is composed of an ‘extended CM framework’ with further details and ‘evaluation criteria’ based on CM functions. This study developed an SSCs list by analyzing Design Control Document (DCD) of Westinghouse AP1000 and also identified evaluation criteria through an extensive literature review. The concept of CM in this study encompasses the entire NPP project life-cycle in order to promote the practical CM application. The results of case-study performed in this paper would provide the SSCs priorities and guidelines for practical configuration management (CM) for sustainable NPP facilities.
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Purba, Julwan Hendry. "Physical Ageing of The Research Reactor Core Structural Materials Due To Neutron Irradiation Exposure: A Review." Jurnal Pengembangan Energi Nuklir 18, no. 2 (March 10, 2017): 93. http://dx.doi.org/10.17146/jpen.2016.18.2.3143.
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A research reactor (RR) is a nuclear reactor that has function to generate and utilize neutron flux and radiation ionization for research purposes and industrial applications. More than 60% of current operating RRs have been operated for 30 years or more. As the time passes, the functional capabilities of structures, systems and components (SSCs) of those RRs deteriorate by physical ageing, which can be caused by neutron irradiation exposure such as irradiation induced dislocation and microstructural changes. To extend the lifetime and/or to avoid unplanned outages, ageing on the safety related SSCs of RRs need to be properly managed. An ageing management is a strategy to engineer, operate, maintenance, and control SSC degradation within acceptablelimits. The purpose of this study is to review physical ageing of the core structural materials of the RRs caused by neutron irradiation exposure. In order to achieve this objective, a wide range of literatures are reviewed. Comprehensive discussions on irradiation behaviors are limited only on reactor vessel and core support structure materials made from zirconium and beryllium as well as their alloys, which are widely used in RRs. It is found that the stability of the mechanical properties of zirconium and beryllium as well as their alloys was mostly affected by the neutron fluences and temperatures.
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Banks, P. J. "Ageing management within British Energy in support of safe, reliable operation and lifetime extension objectives." Kerntechnik 67, no. 4 (August 1, 2002): 200–212. http://dx.doi.org/10.1515/kern-2002-0082.
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Abstract British Energy has established a comprehensive suite of ageing/obsolescence asset management programmes. Through these programmes, the company has developed a thorough understanding of all the potentially significant degradation mechanisms which could affect the systems structures and components (SSCs) which are essential to the safe, reliable operation of their NPPs. The results from these ageing management programmes underwrite the existing design basis safety case, provide trending information for Safety System Reviews (SSRs) and Periodic Safety Reviews (PSRs) and provide data in support of extending the operating lifetimes of the NPPs. This paper describes te UK regulatory framework with respect to ageing management, British Energy’s overall approach to ageing management, The various ageing/obsolescence management programmes established by BEG, including examples of potentially significant ageing issues which have been successfully addressed by these programmes and the manner in which the results from the programmes are used in support of continued operation, SSRs, PSRs, lifetime extension and general performance enhancement.
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St Luce, Shane, and Hiroki Sayama. "Analysis and Visualization of High-Dimensional Dynamical Systems’ Phase Space Using a Network-Based Approach." Complexity 2022 (June 29, 2022): 1–11. http://dx.doi.org/10.1155/2022/3937475.
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The concept of attractors is considered critical in the study of dynamical systems as they represent the set of states that a system gravitates toward. However, it is generally difficult to analyze attractors in complex systems due to multiple reasons including chaos, high-dimensionality, and stochasticity. This paper explores a novel approach to analyzing attractors in complex systems by utilizing networks to represent phase spaces. We accomplish this by discretizing phase space and defining node associations with attractors by finding sink strongly connected components (SSCCs) within these networks. Moreover, the network representation of phase space facilitates the use of well-established techniques of network analysis to study the phase space of a complex system. We show the latter by introducing a new node-based metric called attractivity which can be used in conjunction with the SSCC as they are highly correlated. We demonstrate the proposed method by applying it to several chaotic dynamical systems and a large-scale agent-based social simulation model.
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Tatour, Yasmin, Hadas Bar-Joseph, Ruth Shalgi, and Tamar Ben-Yosef. "Male sterility and reduced female fertility in SCAPER-deficient mice." Human Molecular Genetics 29, no. 13 (June 8, 2020): 2240–49. http://dx.doi.org/10.1093/hmg/ddaa113.
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Abstract Mutations in S-phase cyclin A-associated protein in the endoplasmic reticulum (SCAPER) cause a recessively inherited multisystemic disorder whose main features are retinal degeneration and intellectual disability. SCAPER, originally identified as a cell cycle regulator, was also suggested to be a ciliary protein. Because Scaper mutant males are sterile, we set up to characterize their phenotype. The testes of Scaper mutant mice are significantly smaller than those of WT mice. Histology revealed no signs of spermatogenesis, and seminiferous tubules contained mainly Sertoli cells with a few spermatogonia/spermatogonial stem cells (SSCs). In WT testes, SCAPER is expressed by SSCs and in the various stages of spermatogenesis, as well as in Sertoli cells. In WT spermatozoa SCAPER is not expressed in the flagellum but rather in the head compartment, where it is found both in the nucleus and in the perinuclear region. Scaper mutant females present reduced fertility, manifested by a significantly smaller litter size compared to WT females. Mutant ovaries are similar in size but comprised of significantly less primordial and antral follicles, compared to WT ovaries, while the number of atretic follicles is significantly higher. In WT ovarian follicles SCAPER is expressed in the somatic granulosa cells as well as in the oocyte. In conclusion, our data demonstrate that SCAPER is a crucial component in both male and female reproductive systems. We hypothesize that the reproductive phenotype observed in Scaper mutant mice is rooted in SCAPER’s interaction with cyclin A/Cdk2, which play an important role, however different, in male and female gonads.
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Cancemi, Salvatore Angelo, and Rosa Lo Frano. "Preliminary Analysis of Long-Term Performance of a Piping: Aging and Creep Effects." Materials 14, no. 7 (March 30, 2021): 1703. http://dx.doi.org/10.3390/ma14071703.
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Combining global experience, comprehensive aging knowledge, and predictive methodologies provides ideal prerequisites for the long-term operation strategy (LTO) of a nuclear power plant (NPP). Applying management strategies with an understanding of the ways in which structures relevant for the plant safety perform and interact in their operating environments is of meaningful importance for operating the plant beyond its originally licensed service life. In performing aging studies on the nuclear systems, structure, and components (SSCs), the results are crucial for demonstrating the safety and reliability of the NPP beyond 30 years of nominal operation. In this study, the synergistic effect of a creep mechanism with the alteration suffered by piping material is analyzed by means of MSC©MARC finite element code. Nonlinear analyses were performed to calculate the effects of the long operational period on a primary pipe, assess its degradation, and determine its residual functionality. In these analyses, both homogeneous and inhomogeneous pipe wall thinning are considered, as well as the operating or expected thermal–mechanical loads. The obtained results indicate that thermo–mechanical loads are responsible for pipe deformation, which develops and increases as the transient progresses. Furthermore, an excessive (general or local) wall thinning may determine a dimensional change of the pipe, even causing bending or buckling.
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Tracy, Leslie, and Praveen Kumar Sekhar. "Design and Testing of a Low Voltage Solid-State Circuit Breaker for a DC Distribution System." Energies 13, no. 2 (January 10, 2020): 338. http://dx.doi.org/10.3390/en13020338.
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In this study, a low voltage solid-state circuit breaker (SSCB) was implemented for a DC distribution system using commercially available components. The design process of the high-side static switch was enabled through a voltage bias. Detailed functional testing of the current sensor, high-side switch, thermal ratings, analog to digital conversion (ADC) techniques, and response times of the SSCB was evaluated. The designed SSCB was capable of low-end lighting protection applications and tested at 50 V. A 15 A continuous current rating was obtained, and the minimum response time of the SSCB was nearly 290 times faster than that of conventional AC protection methods. The SSCB was implemented to fill the gap where traditional AC protection schemes have failed. DC distribution systems are capable of extreme faults that can destroy sensitive power electronic equipment. However, continued research and development of the SSCB is helping to revolutionize the power industry and change the current power distribution methods to better utilize clean renewable energy systems.
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Phu, Nguyen Minh. "Overall Optimization and Exergy Analysis of an Air Conditioning System Using a Series-Series Counterflow Arrangement of Water Chillers." International Journal of Air-Conditioning and Refrigeration 27, no. 04 (November 25, 2019): 1950034. http://dx.doi.org/10.1142/s2010132519500342.
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When water chillers are arranged in series-series counterflow (SSCF), the compressor lift of each chiller is decreased in comparison with that of water chillers in parallel. This means that the compressor power of SSCF chillers is lower than that of parallel chillers. In this paper, models of the main components in an air conditioning system were developed and verified to predict the behaviors of the whole system with respect to SSCF chillers. The results showed that performance was maximized with three SSCF chillers when the system was operated with normal set points. The performance was further improved to 26% and decreased with the number of SSCF chillers when the system was operated with optimal set points. The SSCF chiller system also demonstrated higher exergy efficiency regardless of the number of SSCF chillers. The irreversibility of components in SSCF chillers was rather low. However, the irreversibility of the cooling tower and cooling coil was slightly higher and lower, respectively, than those in the parallel chiller system.
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Owen-Smith, Paul, John Wise, and Matthew J. Grieshop. "Season Long Pest Management Efficacy and Spray Characteristics of a Solid Set Canopy Delivery System in High Density Apples." Insects 10, no. 7 (June 29, 2019): 193. http://dx.doi.org/10.3390/insects10070193.
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Solid set canopy delivery systems (SSCDS) are a novel foliar agrochemical delivery system designed as an alternative for airblast sprayers in high density fruit production. This study tested the pest management potential, coverage, and chemical deposition of an SSCDS using commercially available microsprinkler components over the course of a growing season. Spray coverage and deposition for a representative airblast sprayer and SSCDS were evaluated using water sensitive paper and tartrazine dye, respectively. Foliar sprays for pest suppression were applied through both systems, and damage assessments were taken at the midpoint and end of the growing season. SSCDS sprays demonstrated similar levels of coverage on the adaxial leaf surface as airblast sprays, but significantly lower coverage on the abaxial surface. However, mean levels of foliar chemical deposition was generally higher in the SSCDS. Evaluations found minimal arthropod and fungal damage in both airblast and SSCDS treated plots compared to untreated trees. The SSCDS was shown to be a viable alternative to the airblast, with inherent advantages such as rapid application time and improved worker safety. Furthermore, higher deposition on SSCDS treated foliage supports the hypothesis that SSCDS provide a higher droplet capture rate in the canopy, with less off-target loss and drift than airblast sprayers.
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Baltis, Theodore, Douglas C. Hopkins, James M. Pitaressi, and Donald R. Hazelmyer. "High Thermal-Transient Packaging for a SiC-Based Solid State Circuit Breaker." International Symposium on Microelectronics 2011, no. 1 (January 1, 2011): 000608–18. http://dx.doi.org/10.4071/isom-2011-wa5-paper2.
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Solid-State Circuit Breakers (SSCBs), or Contactors, are critical components in next generation electric aircraft, and must be small in size, fast in response, and have high reliability. Silicon Carbide (SiC) semiconductor switches provide a series of improvements over traditional silicon-based breakers in both electrical and thermal performances. The reported SSCB uses SiC MOSFETs mounted on cast-aluminum traces, cast onto an aluminum nitride (AlN) ceramic co-captured in an aluminum composite baseplate. The system is similar to an AlSiC and Direct-Bonded-Aluminum (DBA) approach. This presentation details the transient thermal characterizations of an SSCB having the highest density in development. Previous work focused on a 30A SSCB that was constructed and tested to show a 300A, 500ns circuit breaking capability. The high density comes from allowing the SiC junctions to pulse to ∼350°C (in 5ms) from a 105°C ambient baseplate. The 30A/300A module was reported in IMAPS HiTEC’10 “Development of a SiC SSPC Module with Advanced High Temperature Packaging,” This paper builds on that paper adding the mechanical results and all new data on the larger, high energy density module with larger die. The objective of the presentation is to introduce (or update) the use of cast composite metal-ceramic structures for high thermal transient applications and document the mechanical stress/strain performance through simulations. The module is in development for military applications and has not been field-tested. This is also developed for Smart-Grid applications in local distribution systems.
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Fu, Qinghua, Abdul Aziz Abdul Rahman, Hui Jiang, Jawad Abbas, and Ubaldo Comite. "Sustainable Supply Chain and Business Performance: The Impact of Strategy, Network Design, Information Systems, and Organizational Structure." Sustainability 14, no. 3 (January 18, 2022): 1080. http://dx.doi.org/10.3390/su14031080.
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Technological advancement and the highly competitive nature of business have forced organizations to use multiple strategies to streamline their business operations. Current research investigates the relationship between sustainable supply chain management (SSCM) and business performance, focusing on operational and financial performance. It provides insights into the operational structure, resource utilization, and the identification of strategic tools needed to strengthen organizational performance. The researchers conducted unstructured interviews with 41 industrialists and analyzed them via open-source coding and deducing reasoning. A questionnaire was developed by analyzing critical scientific literature and unstructured interviews. Empirical responses were taken from 202 industrial corporations. The structural analyses indicate that the effective execution of SSCM significantly improves firms’ operational and financial performance. The findings also provide detailed information about different components of SSCM, namely supply chain strategy (SCS), supply chain network design (SCND), organizational structure, and information system, and explain how it relates to the previous literature review by using a multivariate statistical analysis, followed by structural equation modeling (SEM). The findings of current research highlight the significant role of SSC in accelerating firms’ operational and financial performance and suggest that SSCM should be taken as a secondary strategy and must be integrated with the overall business strategy.
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Chernukha, Nikita. "Inclusion of Aircraft Crash into NPP Design Bases and Probabilistic Justification of Loads on Civil Structures and Equipment." Earthquake Engineering. Construction Safety, no. 1 (February 25, 2020): 35–47. http://dx.doi.org/10.37153/2618-9283-2020-1-35-47.
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The article is about nuclear power plant (NPP) safety analysis in case of aircraft crash. Specifically, the article considers the following problems: inclusion of aircraft crash into NPP design bases regarding calculation of frequency of an aircraft crash into NPP; aspects of justification of loads on NPP structures, systems and components (SSCs) caused by mechanical action of a primary missile – aircraft fuselage impact.
Probabilistic characteristics of such random parameters as frequency of aircraft crash and direction of aircraft trajectory are determined by the results of analysis of world statistics of aviation accidents. Method of calculation of aircraft crash frequency on structures, buildings and NPP as a whole is presented. It takes into account options of accidental and intentional aircraft crashes and various aircraft approach scenarios.
Procedure of probabilistic justification of loads on civil structures under aircraft impact is described. The loads are specified so as not to exceed allowable value of failure probability of NPP as a whole. Calculation of failure frequency of civil structures of existing NPP is given as an example to show analysis in case of a crash of an aircraft heavier than considered in NPP design.
Procedure of probabilistic justification of dynamic loads on NPP equipment in case of aircraft impact is described. Method of floor response spectra (FRS) calculation with the required non-exceedance probability is given. Probabilistically justified loads in case of intentional aircraft impact (act of terrorism) are also considered. Additionally it is presented how internal forces calculated with the use of FRS with the required non-exceedance probability can be summed to provide analysis of subsystems.
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Khakim, Azizul. "ANALISIS KESELAMATAN TERMOHIDROLIK BULK SHIELDING REAKTOR KARTINI." JURNAL TEKNOLOGI REAKTOR NUKLIR TRI DASA MEGA 17, no. 3 (October 1, 2015): 115. http://dx.doi.org/10.17146/tdm.2015.17.3.2321.
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ABSTRAK ANALISIS KESELAMATAN TERMOHIDROLIK BULK SHIELDING REAKTOR KARTINI. Bulk shielding merupakan fasilitas yang terintegrasi dengan reaktor Kartini yang berfungsi sebagai penyimpanan sementara bahan bakar bekas. Fasilitas ini merupakan fasilitas yang termasuk dalam struktur, sistem dan komponen (SSK) yang penting bagi keselamatan. Salah satu fungsi keselamatan dari sistem penanganan dan penyimpanan bahan bakar adalah mencegah kecelakaan kekritisan yang tak terkendali dan membatasi naiknya temperatur bahan bakar. Analisis keselamatan paling kurang harus mencakup analisis keselamatan dari sisi neutronik dan termo hidrolik Bulk shielding. Analisis termo hidrolik ditujukan untuk memastikan perpindahan panas dan proses pendinginan bahan bakar bekas berjalan baik dan tidak terjadi akumulasi panas yang mengancam integritas bahan bakar. Code tervalidasi PARET/ANL digunakan untuk analisis pendinginan dengan mode konveksi alam. Hasil perhitungan menunjukkan bahwa mode pendinginan konvekasi alam cukup memadai dalam mendinginkan panas sisa tanpa mengakibatkan kenaikan temperatur bahan bakar yang signifikan. Kata kunci: Bulk shielding, bahan bakar bekas, konveksi alam, PARET. ABSTRACT THERMAL HYDRAULIC SAFETY ANALYSIS OF BULK SHIELDING KARTINI REACTOR. Bulk shielding is an integrated facility to Kartini reactor which is used for temporary spent fuels storage. The facility is one of the structures, systems and components (SSCs) important to safety. Among the safety functions of fuel handling and storage are to prevent any uncontrolable criticality accidents and to limit the fuel temperature increase. Safety analyses should, at least, cover neutronic and thermal hydraulic calculations of the bulk shielding. Thermal hydraulic analyses were intended to ensure that heat removal and the process of the spent fuels cooling takes place adequately and no heat accumulation that challenges the fuel integrity. Validated code, PARET/ANL was used for analysing the spent fuels cooling with natural convection mode. The calculations results concluded that natural convection cooling mode can adequately cools down the decay heat without significant increase in fuel temperatur. Keywords: bulk shielding, spent fuels, natural convection, PARET.
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Shoshin, Evgeny A., Valeria V. Strokova, and Zheng Mao Ye. "Comparative Assessment of Effectiveness of Calcium Silicate Dispersions Produced Using Sucrose and Lactose as Components of Composite Cement Binder." Materials Science Forum 1017 (January 2021): 11–20. http://dx.doi.org/10.4028/www.scientific.net/msf.1017.11.
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Silicate micro- and nano-additives are multifunctional in relation to cement systems. Their application can solve a wide range of technological problems while maintaining the economic efficiency of technical solutions. The effect of silicate additives and fillers is determined by their level of dispersion, due to which the technologies for producing nano- and submicro-sized dispersed materials are being developed. The combination of mechanochemical synthesis of modified calcium hydrosilicates with subsequent thermolysis makes it possible to produce calcium silicate dispersions (SCD), which differ in polymodality of the fractional composition including submicro (10–7–10–6 m) and microdimensional (≥10–6 m) modes. The main element of the technology is the use of modifying carbohydrate, which acts as a stabilizer of hydrated phases of silicates. A comparative study of SCD produced using sucrose (sSCD) and lactose (lSCD) revealed the effect of these carbohydrates on the properties of sSCD and lSCD, as well as their effectiveness as a component of cementitious composite binder. It was found that the level of adsorption of modifying carbohydrate determines the physical properties of SCD (granulometry, specific surface area). The relatively high residual content of free sucrose (0.24%) in the composition of sSCD prevents the consolidation of silicates nanoparticles formed during the thermolysis, causes a high content of submicro sized fractions and a high specific surface area with sSCD (26.3 ± 0.7 m2/g). Lactose is absorbed by the silicate phase; the residual content of free lactose does not exceed 0.028% of lSCD. The low content of stabilizing carbohydrate contributes to the development of nanoparticle consolidation, a decrease in the specific surface area of lSCD to 13.0 ± 0.2 m2/g and content of submicrosized fractions. The residual content of free carbohydrates and particle size characteristics of sSCD and lSCD determine the nature of their influence on Cement-SCD-based concrete setting and hardening. The presence of residual sucrose in the composition of sSCD and fine fractions determines the competitive nature of the processes of retardation of hardening and acceleration of hardening of the cement system due to the nucleation effect, as a result of which the curve of the setting time is extreme. In addition, the inhibitory effect of sucrose reduces the strength of concrete on the 7th day. By the 28th day, the inhibitory effect of sucrose has been overcome, and concrete samples demonstrate an 18% increase in compressive strength with a sSCD content of 30%. The low content of residual free lactose in the composition of lSCD causes the nucleation effect. As a result, there is a monotonous reduction in the setting time of concrete mix with an increase in the content of lSCD in the composition of HF, as well as a significant increase in concrete strength (up to 127%) on the 7th day. At the same time, on the 28th day the strength of concrete increases slightly
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Shoshin, Evgeny A., Valeria V. Strokova, and Zheng Mao Ye. "Comparative Assessment of Effectiveness of Calcium Silicate Dispersions Produced Using Sucrose and Lactose as Components of Composite Cement Binder." Materials Science Forum 1017 (January 2021): 11–20. http://dx.doi.org/10.4028/www.scientific.net/msf.1017.11.
Full textAbstract:
Silicate micro- and nano-additives are multifunctional in relation to cement systems. Their application can solve a wide range of technological problems while maintaining the economic efficiency of technical solutions. The effect of silicate additives and fillers is determined by their level of dispersion, due to which the technologies for producing nano- and submicro-sized dispersed materials are being developed. The combination of mechanochemical synthesis of modified calcium hydrosilicates with subsequent thermolysis makes it possible to produce calcium silicate dispersions (SCD), which differ in polymodality of the fractional composition including submicro (10–7–10–6 m) and microdimensional (≥10–6 m) modes. The main element of the technology is the use of modifying carbohydrate, which acts as a stabilizer of hydrated phases of silicates. A comparative study of SCD produced using sucrose (sSCD) and lactose (lSCD) revealed the effect of these carbohydrates on the properties of sSCD and lSCD, as well as their effectiveness as a component of cementitious composite binder. It was found that the level of adsorption of modifying carbohydrate determines the physical properties of SCD (granulometry, specific surface area). The relatively high residual content of free sucrose (0.24%) in the composition of sSCD prevents the consolidation of silicates nanoparticles formed during the thermolysis, causes a high content of submicro sized fractions and a high specific surface area with sSCD (26.3 ± 0.7 m2/g). Lactose is absorbed by the silicate phase; the residual content of free lactose does not exceed 0.028% of lSCD. The low content of stabilizing carbohydrate contributes to the development of nanoparticle consolidation, a decrease in the specific surface area of lSCD to 13.0 ± 0.2 m2/g and content of submicrosized fractions. The residual content of free carbohydrates and particle size characteristics of sSCD and lSCD determine the nature of their influence on Cement-SCD-based concrete setting and hardening. The presence of residual sucrose in the composition of sSCD and fine fractions determines the competitive nature of the processes of retardation of hardening and acceleration of hardening of the cement system due to the nucleation effect, as a result of which the curve of the setting time is extreme. In addition, the inhibitory effect of sucrose reduces the strength of concrete on the 7th day. By the 28th day, the inhibitory effect of sucrose has been overcome, and concrete samples demonstrate an 18% increase in compressive strength with a sSCD content of 30%. The low content of residual free lactose in the composition of lSCD causes the nucleation effect. As a result, there is a monotonous reduction in the setting time of concrete mix with an increase in the content of lSCD in the composition of HF, as well as a significant increase in concrete strength (up to 127%) on the 7th day. At the same time, on the 28th day the strength of concrete increases slightly
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Yadav, M. K., and A. K. Srivastava. "Effective Mixer Design an Important Factor In SSCR Systems for Reduction of NOx from Exhaust of Diesel Engines." Nature Environment and Pollution Technology 21, no. 4 (December 1, 2022): 1753–60. http://dx.doi.org/10.46488/nept.2022.v21i04.030.
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In recent decades, the environment has been seriously polluted by the hazardous exhaust components of diesel engines. The international community, which is dedicated to preserving the harmony between nature and humanity, has taken this seriously and imposed strict regulations on Diesel engine manufacturers regarding the quantity of exhaust components from Diesel engines that may apply to the standards of EURO-VI. The SCR technology attempted to reduce the problem somewhat, but the associated problems of solid particle formation on the pipe walls, ammonia slip, and incomplete NOx reduction led to the development of new technology - solid selective catalytic reduction. The use of solid ammonium salt for ammonia generation has shown better results in NOx reduction and reduction of solid particle formation compared to SCR. However, it was not possible to fully resolve the ammonia slip issue. A uniform flow rate of ammonia through the SCR catalyst can reduce NOx efficiently. In this paper, the role of mixer design in achieving a uniform flow rate of ammonia is investigated in detail. The results show that an optimized mixer design leads to efficient reduction of NOx and thus reduces ammonia slip to a great extent. When the mixer is placed near the ammonia injection point, the most homogeneous ammonia distribution is achieved for flow through the SCR catalyst.
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Ofanson U, Tamunodukobipi D.T, and Nitonye S. "Failure mode effects and criticality analysis (FMECA) using fuzzy logic for ship dynamic positioning (DP) systems." Global Journal of Engineering and Technology Advances 13, no. 1 (October 30, 2022): 038–52. http://dx.doi.org/10.30574/gjeta.2022.13.1.0170.
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Predicting the failure modes effect and criticality analysis (FMECA) of a dynamic positioning (DP) system using fuzzy logic is the aim of this research. The identification of DP systems and subsystems, the classification of failure modes into critical and less-critical levels based on the Risk Priority Number (RPN) to depict the main root causes of failure in the DP system are some critical objectives in support of this goal. The analysis offers details on a number of issues, including the causes of failure modes and their effects on the functionality and dependability of equipment. Based on the information provided, it was determined that a number of failure modes produced identical RPN values, and that the ranking scale was erroneous. A new method was tested but could not really prioritize the failure modes with same RPN because of the few choices in the severity, occurrence and detection template. To compensate for this, excel ranking function was employed putting severity, occurrence and detection as key criteria for ranking. Due to the high severity and occurrence index, the RPN ranking results show that the faulty DP system component identified for the scenario SSTs (F1) is categorized as very critical. SSCs (F12), SSPr (F7), SSTs(F2), and SSPs(F15) are additional critical failures. In the study, data analysis and validation were done using a fuzzy rule system based on MATLAB. From the findings, it can be inferred that the failure modes F1, F2, F5, F6, F7, F8, F10, F11, and F15 have values of a similar type of RPN. According to the initial RPN risk level results; there are 19 failure modes in the medium risk level, 2 in the low risk level and 1 in the high risk level. In the final RPN-based risk level results, there are 18 failure scenarios in the low risk level and 4 in the medium risk level. In contrast, there are 5 failure modes in the fuzzy RPN low risk level and 17 failure scenarios in the medium risk level. Without fuzzy logic, the justification score on traditional FMECA can be given directly. This makes traditional FMECA ABS show greater risk than fuzzy FMECA. The failure modes with the highest RPN values were treated as critical parts, so it was recommended that the highest value of RPN be given special attention by making the necessary repairs or replacements in order to lengthen the equipment's lifespan.
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Lin, Ming-Shian. "A Regulated Pulse Current Driver with Spread Spectrum Clock Generator." Electronics 10, no. 21 (October 30, 2021): 2661. http://dx.doi.org/10.3390/electronics10212661.
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This paper presents a regulated pulse current driver with a spread spectrum clock generator (SSCG) to lower the electromagnetic interference (EMI) effect. An SSCG is used and implemented by applying a triangular wave to modulate a voltage-controlled oscillator (VCO). The results show a 7 dBm reduction in the peak power level with a frequency deviation of 10%, demonstrating that the dominate harmonic is spread and distributed to adjacent frequencies, and the magnitude of harmonics is significantly reduced. The results demonstrate that the driver with a spread spectrum clock generator would help to reduce interference in sensitive electronic components and be suitable for portable consumer electronics applications.
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Saarenheimo, Arja, Michael Borgerhoff, Kim Calonius, Anthony Darraba, Alexandre Hamelin, Sara Ghadimi Khasraghy, Amin Karbassi, et al. "Numerical studies on vibration propagation and damping test V1." Rakenteiden Mekaniikka 51, no. 1 (August 16, 2018): 55–80. http://dx.doi.org/10.23998/rm.68954.
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Earthquakes and aircraft impacts induce vibrations that propagate throughout the entire building and they need to be considered in designing SSCs (Structures, Systems and Components). Mainly linear calculation methods have been in use in design practice and the codes and standards consider damping ratios only for linear structural analyses. Induced vibrations, especially in damaged concrete structures, have not been studied extensively enough for optimization of structural frameworks and/or qualified systems and components. Experimental data on damping properties of damaged reinforced concrete are needed also for benchmarking analysis programs and methods.
Recently, within IMPACT project, a new type of test series considering vibration propagation has been carried out at VTT. The test target is a reinforced concrete structure with two parallel walls connected to a floor slab. The front wall is additionally supported by triangular shaped side walls which are connected to the floor slab too. The test structure is supported on elastomeric bearing pads, with back pipes effective mainly in compression and with bars effective in tension. In order to obtain information on vibration propagation in damaged concrete structure at different levels of damage grades the same structure was tested six times. At each time the mass of the deformable stainless steel missile was 50 kg. The hit point located in the middle of the front wall. The impact velocity was about 110 m/s in the first four tests (V1A-D) and about 60 m/s in the remaining two tests (V1E and F). In this paper, numerical results on tests V1A and V1F are compared with the corresponding experimental ones.
The calculated results, such as accelerations, displacements, their response spectra and strains, are compared with experimental measurements. Five finite element (FE) programs are used in computations: Abaqus, Europlexus, LS-DYNA, SOFiSTiK and an in-house code (IHC).
Most of the FE-codes in the present study use shell elements. In Abaqus and SOFiSTiK non-linear behaviour of shell section is modelled by dividing the cross section into layers. Reinforcements are also modelled as layers. In Europlexus and IHC, an alternative approach is adopted in which the non-linear behaviour of concrete and reinforcement is homogenized beforehand in the shell thickness direction obtaining relations between stress resultants and generalized strains valid for the shell section. In LS-DYNA, 3D solid elements for modelling concrete and beam elements for modelling reinforcements are used.
Equations of motion are integrated with explicit central difference time integration method, except in SOFiSTiK implicit integration method is used. Modelling and computations with the mentioned FE-programs are made independently of each other. Computations with LS-DYNA are carried out as blind exercises.
Consideration of the results from benchmarking point of view is still on-going. However it is evident that analysed results follow reasonable well test results in main design parameter level such as maximum displacements, accelerations and strains. Also frequency spectra are estimated reasonably well.
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Gofur, Md Royhan. "Recent advances on identification of spermatogonial stem cells and their niche." Asian Journal of Medical and Biological Research 6, no. 3 (October 17, 2020): 375–82. http://dx.doi.org/10.3329/ajmbr.v6i3.49785.
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Spermatogonial stem cells (SSCs) are the most primitive spermatogonia in the testis. A balance between the self-renewal and differentiation of SSCs, strictly controlled in a special „niche‟ microenvironment in the seminiferous tubules (SSC niche), is essential to maintain normal spermatogenesis. Since the 1950s, many experimental methods, including histology, immunostaining, whole-mount analyses, and pulse-chase labeling, had been used in attempts to identify SSCs. Recent studies demonstrate that Aundiffseem to possess variable levels of stem cell potential to act as SSCs; GFRα1+ population in As has the greatest potential to act as SSCs (can consider as actual SSCs) whereas NGN3+ population in Aundiffhas comparatively much lower potential to act as SSCs (can consider as potential SSCs). The precise identity of SSCs is still being refined. Sertoli cells, directly interact with SSCs, and interstial cells including Leydig cells, testicular macrophages, peritubularmyoid cells and vascular smooth muscle cells, control the proliferation and differentiation of SSCs through the secretion of extrinsic factors, constitute the cellular components of SSC niche which preferentially locates in the region of seminiferous tubules adjacent to the interstitium that always coincide blood vessels.
Asian J. Med. Biol. Res. September 2020, 6(3): 375-382
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Riley, Simon C. "Student Selected Components (SSCs): AMEE Guide No 46." Medical Teacher 31, no. 10 (January 2009): 885–94. http://dx.doi.org/10.3109/01421590903261096.
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Murdoch-Eaton, Deborah. "Student Selected Components (SSCs): Guide supplement 46.1 – Viewpoint." Medical Teacher 33, no. 9 (August 19, 2011): 762–64. http://dx.doi.org/10.3109/0142159x.2011.547957.
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Alexandrov, Yury I. "The subject of behavior and dynamics of its states." Российский психологический журнал 15, no. 2/1 (September 30, 2018): 131–50. http://dx.doi.org/10.21702/rpj.2018.2.1.8.
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Introduction. The concept of a “subject of behavior” (SB) was formulated within the system-evolutionary theory in systemic psychophysiology. It is argued that the development of the concept of SB requires describing other components of this internally consistent theory.
Theoretical review. This section reviews the theoretical and empirical grounds used by V.B. Shvyrkov to formulate the original foundations of the concepts of SB and “state of the subject of behavior” (SSB). SB is defined as the whole set of functional systems (elements of subjective experience) comprising memory. SSB is defined as a section of functional systems (part of the whole set) that are formed at different stages of individual development and simultaneously actualized in order to provide the deployment of a certain step of the behavioral continuum. Behavior is considered as the dynamics of SSBs, i.e. the transition from the state corresponding to one behavioral act of the continuum to the state corresponding to the next behavioral act.
Results. This section reviews the results of theoretical and empirical development of the concepts of SB and SSB that was aimed to expand their factually supported meaning. This development has been implemented via the research paradigm of system psychophysiology representing a field of multidisciplinary studies focused on the mechanisms of formation and actualisation of experience in human and other animals during individual and collective behavior. I review neurogenetic bases of experience formation; dynamics of the formation of the structure of experience within a strategic game; variability of SSBs during consequent behaviors; the role of learning history during formation of the structure of experience; specific characteristics of various domains of experience; the unified theory of consciousness and emotion along with its implications; dynamics of SSBs underlying regression; properties of various forms of social interaction in individuals with holistic and analytical mentalities; the system mechanisms of moral judgement of actions; and results of mathematical modelling of SB formation.
Conclusions. Results of the reviewed studies of SB and SSB demonstrate heuristic value of these concepts and their potential as methodological tools for coordinated development in various fields of psychology and neuroscience.
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Tan, Kun, Hye-Won Song, Merlin Thompson, Sarah Munyoki, Meena Sukhwani, Tung-Chin Hsieh, Kyle E. Orwig, and Miles F. Wilkinson. "Transcriptome profiling reveals signaling conditions dictating human spermatogonia fate in vitro." Proceedings of the National Academy of Sciences 117, no. 30 (July 13, 2020): 17832–41. http://dx.doi.org/10.1073/pnas.2000362117.
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Spermatogonial stem cells (SSCs) are essential for the generation of sperm and have potential therapeutic value for treating male infertility, which afflicts >100 million men world-wide. While much has been learned about rodent SSCs, human SSCs remain poorly understood. Here, we molecularly characterize human SSCs and define conditions favoring their culture. To achieve this, we first identified a cell-surface protein, PLPPR3, that allowed purification of human primitive undifferentiated spermatogonia (uSPG) highly enriched for SSCs. Comparative RNA-sequencing analysis of these enriched SSCs with differentiating SPG (KIT+cells) revealed the full complement of genes that shift expression during this developmental transition, including genes encoding key components in the TGF-β, GDNF, AKT, and JAK-STAT signaling pathways. We examined the effect of manipulating these signaling pathways on cultured human SPG using both conventional approaches and single-cell RNA-sequencing analysis. This revealed that GDNF and BMP8B broadly support human SPG culture, while activin A selectively supports more advanced human SPG. One condition—AKT pathway inhibition—had the unique ability to selectively support the culture of primitive human uSPG. This raises the possibility that supplementation with an AKT inhibitor could be used to culture human SSCs in vitro for therapeutic applications.
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M. Gilbert, Andrea, and James R. Graham. "Kinematic Masses of Super Star Clusters in NGC 1569." Symposium - International Astronomical Union 207 (2002): 471–73. http://dx.doi.org/10.1017/s0074180900224248.
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We summarize recent results from our study of the massive young super star clusters (SSCs) in the dwarf galaxy NGC 1569, and present new high-resolution NIRSPEC spectra that permit the measurement of a cluster's intrinsic stellar velocity dispersion. Thus we derive kinematic masses for the two brightest SSCs: 2.3 × 105 Msun for SSC B, and 3.9 × 105 and 4.4 × 105 Msun for the two components of SSC A.
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Ibtisham, Fahar, and Ali Honaramooz. "Spermatogonial Stem Cells for In Vitro Spermatogenesis and In Vivo Restoration of Fertility." Cells 9, no. 3 (March 18, 2020): 745. http://dx.doi.org/10.3390/cells9030745.
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Spermatogonial stem cells (SSCs) are the only adult stem cells capable of passing genes onto the next generation. SSCs also have the potential to provide important knowledge about stem cells in general and to offer critical in vitro and in vivo applications in assisted reproductive technologies. After century-long research, proof-of-principle culture systems have been introduced to support the in vitro differentiation of SSCs from rodent models into haploid male germ cells. Despite recent progress in organotypic testicular tissue culture and two-dimensional or three-dimensional cell culture systems, to achieve complete in vitro spermatogenesis (IVS) using non-rodent species remains challenging. Successful in vitro production of human haploid male germ cells will foster hopes of preserving the fertility potential of prepubertal cancer patients who frequently face infertility due to the gonadotoxic side-effects of cancer treatment. Moreover, the development of optimal systems for IVS would allow designing experiments that are otherwise difficult or impossible to be performed directly in vivo, such as genetic manipulation of germ cells or correction of genetic disorders. This review outlines the recent progress in the use of SSCs for IVS and potential in vivo applications for the restoration of fertility.
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Farhat, Maha, Marina Moletta-Denat, Jacques Frère, Séverine Onillon, Marie-Cécile Trouilhé, and Enric Robine. "Effects of Disinfection on Legionella spp., Eukarya, and Biofilms in a Hot Water System." Applied and Environmental Microbiology 78, no. 19 (July 20, 2012): 6850–58. http://dx.doi.org/10.1128/aem.00831-12.
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ABSTRACTLegionellaspecies are frequently detected in hot water systems, attached to the surface as a biofilm. In this work, the dynamics ofLegionellaspp. and diverse bacteria and eukarya associated together in the biofilm, coming from a pilot scale 1 system simulating a real hot water system, were investigated throughout 6 months after two successive heat shock treatments followed by three successive chemical treatments. Community structure was assessed by a fingerprint technique, single-strand conformation polymorphism (SSCP). In addition, the diversity and dynamics ofLegionellaand eukarya were investigated by small-subunit (SSU) ribosomal cloning and sequencing. Our results showed that pathogenicLegionellaspecies remained after the heat shock and chemical treatments (Legionella pneumophilaandLegionella anisa, respectively). The biofilm was not removed, and the bacterial community structure was transitorily affected by the treatments. Moreover, several amoebae had been detected in the biofilm before treatments (Thecamoebaesp.,Vannellasp., andHartmanella vermiformis) and after the first heat shock treatment, but onlyH. vermiformisremained. However, another protozoan affiliated with Alveolata, which is known as a host cell forLegionella, dominated the eukaryal species after the second heat shock and chemical treatment tests. Therefore, effectiveLegionelladisinfection may be dependent on the elimination of these important microbial components. We suggest that eradicatingLegionellain hot water networks requires better study of bacterial and eukaryal species associated withLegionellain biofilms.
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Takase, Hinako M., and Roeland Nusse. "Paracrine Wnt/β-catenin signaling mediates proliferation of undifferentiated spermatogonia in the adult mouse testis." Proceedings of the National Academy of Sciences 113, no. 11 (February 29, 2016): E1489—E1497. http://dx.doi.org/10.1073/pnas.1601461113.
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Spermatogonial stem cells (SSCs) fuel the production of male germ cells but the mechanisms behind SSC self-renewal, proliferation, and differentiation are still poorly understood. Using the Wnt target gene Axin2 and genetic lineage-tracing experiments, we found that undifferentiated spermatogonia, comprising SSCs and transit amplifying progenitor cells, respond to Wnt/β-catenin signals. Genetic elimination of β-catenin indicates that Wnt/β-catenin signaling promotes the proliferation of these cells. Signaling is likely initiated by Wnt6, which is uniquely expressed by neighboring Sertoli cells, the only somatic cells in the seminiferous tubule that support germ cells and act as a niche for SSCs. Therefore, unlike other stem cell systems where Wnt/β-catenin signaling is implicated in self-renewal, the Wnt pathway in the testis specifically contributes to the proliferation of SSCs and progenitor cells.
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Dym, M., Z. He, J. Jiang, D. Pant, and M. Kokkinaki. "Spermatogonial stem cells: unlimited potential." Reproduction, Fertility and Development 21, no. 1 (2009): 15. http://dx.doi.org/10.1071/rd08221.
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Recent reports have demonstrated that adult cells can be reprogrammed to pluripotency, but mostly with genes delivered using retroviruses. Some of the genes are cancer causing; thus, these adult-derived embryonic stem (ES)-like cells cannot be used for therapy to cure human diseases. Remarkably, it has also been demonstrated recently by several groups that, in mice, spermatogonial stem cells (SSCs) can be reprogrammed to ES-like cells without the necessity of exogenously added genes. SSCs constitute one of the most important stem cell systems in the body, not only because they produce spermatozoa that transmit genetic information from generation to generation, but also because of the recent studies showing their remarkable plasticity. Very little is known about SSCs in humans, except for the earlier work of Clermont and colleagues who demonstrated that there are Adark and Apale spermatogonia, with the Adark referred to as the reserve stem cells and the Apale being the renewing stem cells. We now demonstrate that G protein-coupled receptor 125 (GPR125) may be a marker for human SSCs. Putative human SSCs can also be reprogrammed to pluripotency. We were able to achieve this result without the addition of genes, suggesting that human SSCs have considerable potential for cell-based, autologous organ regeneration therapy for various diseases.
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Ogundipe, Olayinka A. "Student selected components as an educational platform for teaching medical students about clinical pharmacology and quality improvement activities." International Journal of Basic & Clinical Pharmacology 10, no. 3 (February 22, 2021): 309. http://dx.doi.org/10.18203/2319-2003.ijbcp20210563.
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Student selected components (SSCs) are increasingly described elements of medical undergraduate education, training and curricula. SSCs offer the potential for integration into both traditional (‘pre-clinical’ versus ‘clinical’) medical curricula, as well as into other innovative or evolving medical training curricula. This article employs a structured and descriptive approach to exemplify the process by which year 1 medical students were supported in a practical manner to undertake a distinct small group SSC project. In this illustration, the SSC was focused on a quality improvement (QI) topic of relevance to clinical pharmacology and therapeutics (CPT), and involved a review of the anticholinergic burden of inpatient prescriptions for a defined cohort. The SSC was completed in the context of a teaching hospital’s medicine of the elderly (MoE) clinical service. In a sequential manner, the paper describes experiential learning points from the perspective of a supervisor of an SSC project. The paper offers educational value with a potential for generalisable application to non-clinical and clinical educationalists. Furthermore, the paper offers guidance to supervisors, teachers, tutors and facilitators, with encouragement to consider how they may design similar projects for the training of undergraduate medical students in centres that they are affiliated with. The paper also highlights another key driver for productive SSCs i.e. the central principle of striving to promote projects and activities that support active student engagement, rather than merely passive inclusion.
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Kubota, Hiroshi, and Ralph L. Brinster. "Spermatogonial stem cells†." Biology of Reproduction 99, no. 1 (March 30, 2018): 52–74. http://dx.doi.org/10.1093/biolre/ioy077.
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Abstract Spermatogonial stem cells (SSCs) are the most primitive spermatogonia in the testis and have an essential role to maintain highly productive spermatogenesis by self-renewal and continuous generation of daughter spermatogonia that differentiate into spermatozoa, transmitting genetic information to the next generation. Since the 1950s, many experimental methods, including histology, immunostaining, whole-mount analyses, and pulse-chase labeling, had been used in attempts to identify SSCs, but without success. In 1994, a spermatogonial transplantation method was reported that established a quantitative functional assay to identify SSCs by evaluating their ability to both self-renew and differentiate to spermatozoa. The system was originally developed using mice and subsequently extended to nonrodents, including domestic animals and humans. Availability of the functional assay for SSCs has made it possible to develop culture systems for their ex vivo expansion, which dramatically advanced germ cell biology and allowed medical and agricultural applications. In coming years, SSCs will be increasingly used to understand their regulation, as well as in germline modification, including gene correction, enhancement of male fertility, and conversion of somatic cells to biologically competent male germline cells.
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Ding, Jianhua, Qi Yao, and Lei Jiang. "Comparisons of Scotopic/Photopic Ratios Using 2- and 10-Degree Spectral Sensitivity Curves." Applied Sciences 9, no. 20 (October 22, 2019): 4471. http://dx.doi.org/10.3390/app9204471.
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Despite the fact that a 2-degree spectral sensitivity curve (SSC) is extensively used in scientific research and relevant applications, the choice between the 10-degree or the 2-degree photopic SSCs in practical applications for the calculation of scotopic/photopic ratios (S/P ratios) depends on actual needs. We examined S/P ratios for more than 300 light sources for correlated colour temperatures (CCTs) from 2000 K to 8000 K and blackbody radiant spectra from 10000 K to 45000 K using 2- and 10-degree SSCs. Results showed that the ratio of the S/P values calculated using the 10-degree and 2-degree SSCs was approximately equal to 0.916. The average mesopic luminance difference increased from 0% to 5.7% at a photopic adaptation luminance from 0.005 to 5 cd/m2. For most practical applications, the mesopic luminance values calculated using these two SSCs were different by several percentage units, yet these differences could be neglected. At extremely high CCTs over 10000 K, the mesopic luminance difference may approximate the maximum value of 16%. This work proposes the conversion coefficients for S/P ratios and the transforming mesopic luminance values calculated for 2- and 10-degree SSC systems. These results may help researchers clarify differences between the S/P ratios calculated using different SSCs.
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Fedosov, Alexander, Paul Zaharias, and Nicolas Puillandre. "A phylogeny-aware approach reveals unexpected venom components in divergent lineages of cone snails." Proceedings of the Royal Society B: Biological Sciences 288, no. 1954 (July 7, 2021): 20211017. http://dx.doi.org/10.1098/rspb.2021.1017.
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Marine gastropods of the genus Conus are renowned for their remarkable diversity and deadly venoms. While Conus venoms are increasingly well studied for their biomedical applications, we know surprisingly little about venom composition in other lineages of Conidae. We performed comprehensive venom transcriptomic profiling for Conasprella coriolisi and Pygmaeconus traillii , first time for both respective genera. We complemented reference-based transcriptome annotation by a de novo toxin prediction guided by phylogeny, which involved transcriptomic data on two additional ‘divergent’ cone snail lineages, Profundiconus , and Californiconus . We identified toxin clusters (SSCs) shared among all or some of the four analysed genera based on the identity of the signal region—a molecular tag present in toxins. In total, 116 and 98 putative toxins represent 29 and 28 toxin gene superfamilies in Conasprella and Pygmaeconus , respectively; about quarter of these only found by semi-manual annotation of the SSCs. Two rare gene superfamilies, originally identified from fish-hunting cone snails, were detected outside Conus rather unexpectedly, so we further investigated their distribution across Conidae radiation. We demonstrate that both these, in fact, are ubiquitous in Conidae, sometimes with extremely high expression. Our findings demonstrate how a phylogeny-aware approach circumvents methodological caveats of similarity-based transcriptome annotation.
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Moura, Catarina Costa, Rahul S. Tare, Richard O. C. Oreffo, and Sumeet Mahajan. "Raman spectroscopy and coherent anti-Stokes Raman scattering imaging: prospective tools for monitoring skeletal cells and skeletal regeneration." Journal of The Royal Society Interface 13, no. 118 (May 2016): 20160182. http://dx.doi.org/10.1098/rsif.2016.0182.
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The use of skeletal stem cells (SSCs) for cell-based therapies is currently one of the most promising areas for skeletal disease treatment and skeletal tissue repair. The ability for controlled modification of SSCs could provide significant therapeutic potential in regenerative medicine, with the prospect to permanently repopulate a host with stem cells and their progeny. Currently, SSC differentiation into the stromal lineages of bone, fat and cartilage is assessed using different approaches that typically require cell fixation or lysis, which are invasive or even destructive. Raman spectroscopy and coherent anti-Stokes Raman scattering (CARS) microscopy present an exciting alternative for studying biological systems in their natural state, without any perturbation. Here we review the applications of Raman spectroscopy and CARS imaging in stem-cell research, and discuss the potential of these two techniques for evaluating SSCs, skeletal tissues and skeletal regeneration as an exemplar.
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M Amrullah Effendi, Hasruddin, and Fauziyah Harahap. "Developing The Search, Solve, Create, And Share (SSCS) - Based Student Worksheets In Biology Learning." Jurnal Pendidikan Indonesia 2, no. 1 (January 25, 2021): 161–70. http://dx.doi.org/10.36418/japendi.v2i1.85.
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The SSCS learning that is collaborated with student worksheets can enhance students more actively in learning because this process can facilitate students in finding and building knowledge to solve problems. The method applied a Research and Development (R&D) adapted from Borg and Gall model. This study was only carried out until the development stage. The results showed that the SSCS-based student worksheets according to material experts containing the aspects of content eligibility of 85.19% with an excellent/eligible category, the presentation eligibility of 85% with an excellent/eligible category, and the SSCS components of 85.26% with an excellent/eligible category. Meanwhile, according to design experts containing the aspects of cover design of 90% with an excellent/eligible category, the cover typography of 100% with an excellent/eligible category, the content design of student worksheet of 87.50 with an excellent/eligible category, and the content illustration of student worksheet of 81.25% with an excellent/eligible category. Based on the teachers’ responses showed an excellent/eligible category, with total score of the teachers’ assessment of 92.17%. The results of students’ responses based on individual tests of 78.13% with an excellent category, small group tests of 78.24% with an excellent category as well as the limited field tests of 81.48% with an excellent category.
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Mouchtouri, Varvara, Diederik Van Reusel, Nikolaos Bitsolas, Antonis Katsioulis, Raf Van den Bogaert, Björn Helewaut, Inge Steenhout, Dion Damman, Miguel Dávila Cornejo, and Christos Hadjichristodoulou. "European Web-Based Platform for Recording International Health Regulations Ship Sanitation Certificates: Results and Perspectives." International Journal of Environmental Research and Public Health 15, no. 9 (August 24, 2018): 1833. http://dx.doi.org/10.3390/ijerph15091833.
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The purpose of this study was to report the data analysis results from the International Health Regulations (2005) Ship Sanitation Certificates (SSCs), recorded in the European Information System (EIS). International sea trade and population movements by ships can contribute to the global spread of diseases. SSCs are issued to ensure the implementation of control measures if a public health risk exists on board. EIS designed according to the World Health Organization (WHO) “Handbook for Inspection of Ships and Issuance of SSC”. Inspection data were recorded and SSCs issued by inspectors working at European ports were analysed. From July 2011–February 2017, 107 inspectors working at 54 ports in 11 countries inspected 5579 ships. Of these, there were 29 types under 85 flags (including 19 EU Member States flags). As per IHR (2005) 10,281 Ship Sanitation Control Exception Certificates (SSCECs) and 296 Ship Sanitation Control Certificates (SSCCs) were issued, 74 extensions to existing SSCs were given, 7565 inspection findings were recorded, and 47 inspections were recorded without issuing an SSC. The most frequent inspection findings were the lack of potable water quality monitoring reports (23%). Ships aged ≥12 years (odds ratio, OR = 1.77, 95% confidence intervals, CI = 1.37–2.29) with an absence of cargo at time of inspection (OR = 3.36, 95% CI = 2.51–4.50) had a higher probability of receiving an SSCC, while ships under the EU MS flag had a lower probability of having inspection findings (OR = 0.72, 95% CI = 0.66–0.79). Risk factors to prioritise the inspections according to IHR were identified by using the EIS. A global information system, or connection of national or regional information systems and data exchange, could help to better implement SSCs using common standards and procedures.
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Taylor, J. R., M. Lester, and T. K. Yeoman. "A superposed epoch analysis of geomagnetic storms." Annales Geophysicae 12, no. 7 (June 30, 1994): 612–24. http://dx.doi.org/10.1007/s00585-994-0612-4.
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Abstract. A superposed epoch analysis of geomagnetic storms has been undertaken. The storms are categorised via their intensity (as defined by the Dst index). Storms have also been classified here as either storm sudden commencements (SSCs) or storm gradual commencements (SGCs, that is all storms which did not begin with a sudden commencement). The prevailing solar wind conditions defined by the parameters solar wind speed (vsw), density (ρsw) and pressure (Psw) and the total field and the components of the interplanetary magnetic field (IMF) during the storms in each category have been investigated by a superposed epoch analysis. The southward component of the IMF, appears to be the controlling parameter for the generation of small SGCs (-100 nT< minimum Dst ≤ -50 nT for ≥ 4 h), but for SSCs of the same intensity solar wind pressure is dominant. However, for large SSCs (minimum Dst ≤ -100 nT for ≥ 4 h) the solar wind speed is the controlling parameter. It is also demonstrated that for larger storms magnetic activity is not solely driven by the accumulation of substorm activity, but substantial energy is directly input via the dayside. Furthermore, there is evidence that SSCs are caused by the passage of a coronal mass ejection, whereas SGCs result from the passage of a high speed/ slow speed coronal stream interface. Storms are also grouped by the sign of Bz during the first hour epoch after the onset. The sign of Bz at t = +1 h is the dominant sign of the Bz for ~24 h before the onset. The total energy released during storms for which Bz was initially positive is, however, of the same order as for storms where Bz was initially negative.
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Hekmat, Farzaneh, Husnu Emrah Unalan, and Saeed Shahrokhian. "Biomass-derived wearable energy storage systems based on poplar tree-cotton fibers coupled with binary nickel–cobalt nanostructures." Sustainable Energy & Fuels 4, no. 2 (2020): 643–54. http://dx.doi.org/10.1039/c9se00565j.
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We demonstrated symmetric and asymmetric supercapacitors (SSCs and ASCs) based on core/shell-like Ni–Co oxide@cotton//Fe2O3–carbon nanotubes@cotton that are capable of storing a remarkable amount of energy, while retaining a high power density and long cycle life.
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Jung, Jin Gyoung, Young Mok Lee, Jin Nam Kim, Tae Min Kim, Ji Hye Shin, Tae Hyun Kim, Jeong Mook Lim, and Jae Yong Han. "The reversible developmental unipotency of germ cells in chicken." REPRODUCTION 139, no. 1 (January 2010): 113–19. http://dx.doi.org/10.1530/rep-09-0265.
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We recently developed bimodal germline chimera production approaches by transfer of primordial germ cells (PGCs) or embryonic germ cells (EGCs) into embryos and by transplantation of spermatogonial stem cells (SSCs) or germline stem cells (GSCs) into adult testes. This study was undertaken to investigate the reversible developmental unipotency of chicken germ cells using our established germline chimera production systems. First, we transferred freshly isolated SSCs from adult testis or in vitro cultured GSCs into stage X and stage 14–16 embryos, and we found that these transferred SSCs/GSCs could migrate to the recipient embryonic gonads. Of the 527 embryos that received SSCs or GSCs, 135 yielded hatchlings. Of 17 sexually mature males (35.3%), six were confirmed as germline chimeras through testcross analysis resulting in an average germline transmission efficiency of 1.3%. Second, PGCs/EGCs, germ cells isolated from embryonic gonads were transplanted into adult testes. The EGC transplantation induced germline transmission, whereas the PGC transplantation did not. The germline transmission efficiency was 12.5 fold higher (16.3 vs 1.3%) in EGC transplantation into testis (EGCs to adult testis) than that in SSC/GSC transfer into embryos (testicular germ cells to embryo stage). In conclusion, chicken germ cells from different developmental stages can (de)differentiate into gametes even after the germ cell developmental clock is set back or ahead. Use of germ cell reversible unipotency might improve the efficiency of germ cell-mediated germline transmission.
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Losowsky, MS. "Student Selected Components (SSCs) in medical history: using the Thackray Museum as a resource." Clinical Teacher 4, no. 1 (February 23, 2007): 25–30. http://dx.doi.org/10.1111/j.1743-498x.2007.00113.x.
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Garcia, Joe, Russell Shannon, Aaron Jacobson, William Mosca, Michael Burger, and Roberto Maldonado. "Powerful authentication regime applicable to naval OFP integrated development (PARANOID): a vision for non-circumventable code signing and traceability for embedded avionics software." Journal of Defense Analytics and Logistics 5, no. 1 (June 23, 2021): 46–76. http://dx.doi.org/10.1108/jdal-03-2020-0006.
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Purpose This paper aims to describe an effort to provide for a robust and secure software development paradigm intended to support DevSecOps in a naval aviation enterprise (NAE) software support activity (SSA), with said paradigm supporting strong traceability and provability concerning the SSA’s output product, known as an operational flight program (OFP). Through a secure development environment (SDE), each critical software development function performed on said OFP during its development has a corresponding record represented on a blockchain. Design/methodology/approach An SDE is implemented as a virtual machine or container incorporating software development tools that are modified to support blockchain transactions. Each critical software development function, e.g. editing, compiling, linking, generates a blockchain transaction message with associated information embedded in the output of a said function that, together, can be used to prove integrity and support traceability. An attestation process is used to provide proof that the toolchain containing SDE is not subject to unauthorized modification at the time said critical function is performed. Findings Blockchain methods are shown to be a viable approach for supporting exhaustive traceability and strong provability of development system integrity for mission-critical software produced by an NAE SSA for NAE embedded systems software. Practical implications A blockchain-based authentication approach that could be implemented at the OFP point-of-load would provide for fine-grain authentication of all OFP software components, with each component or module having its own proof-of-integrity (including the integrity of the used development tools) over its entire development history. Originality/value Many SSAs have established control procedures for development such as check-out/check-in. This does not prove the SSA output software is secure. For one thing, a build system does not necessarily enforce procedures in a way that is determinable from the output. Furthermore, the SSA toolchain itself could be attacked. The approach described in this paper enforces security policy and embeds information into the output of every development function that can be cross-referenced to blockchain transaction records for provability and traceability that only trusted tools, free from unauthorized modifications, are used in software development. A key original concept of this approach is that it treats assigned developer time as a transferable digital currency.
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Zhao, Lan, and Yi Pan. "SSCS: A Stage Supervised Subtyping System for Colorectal Cancer." Biomedicines 9, no. 12 (December 2, 2021): 1815. http://dx.doi.org/10.3390/biomedicines9121815.
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Colorectal cancer (CRC) is heterogeneous and deadly, and the exact cause of the disease is unknown. Recent progress indicated that CRC is not a single disease, but a group of diseases with significant heterogeneity. Three previous CRC subtyping systems: microsatellite instability (MSI), consensus molecular subtypes (CMS), and tumor-node-metastases (TNM) stage were evaluated for their molecular and clinical implications. Results suggested that the MSI and CMS systems are prognostic and predictive mostly in early-stage CRC. As the stage remains an influential factor for CRC subtype analysis, we developed a new subtyping system named stage supervised CRC subtypes (SSCS), in order to better stratify CRC biologically and clinically. Our subtyping system can be used to classify CRC patients into five subtypes (SSCS1-5). SSCS1 was found to have the highest frequency of MSI-H cases compared to the remaining four subtypes. SSCS2 had the most favorable prognosis, whereas the worst prognosis was seen in SSCS4. SSCS3 had cell cycle and metabolism-related gene sets upregulation, and SSCS5 subtype was enriched with amplicon-associated gene sets. Moreover, tumor-infiltrating fibroblast was found to be predictive for poor disease-free survival (DFS) only within the SSCS4 subtype. Conventional dendritic cells (cDC), on the contrary, were associated with favorable DFS in the SSCS3 subtype. Our study provides a new subtyping system SSCS, which can be used for better stratify CRC patients compared to current standards. Further exploration of the subtype-specific cell types has the potential to be novel therapies for CRC.
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Huang, J. H., Z. G. Deng, and Y. N. Fu. "Bulge Formation in Late-type Galaxies — Cuspy- vs Soft-core Dark Matter Density Profiles." Symposium - International Astronomical Union 220 (2004): 325–26. http://dx.doi.org/10.1017/s0074180900183536.
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Observational data increasingly indicate that the mergers of galaxies, even minor mergers, can trigger the formation of a set of SSCs within galaxies. the follow-up, dynamical evolution of SSCs in a configuration of dark matter (DM) dominated systems would be basically similar to what we simulated in this work. the scenario that we propose yields a series of results comparable to the relevant observations. Most notable are two points. One is that the low bulge detection rate in very late-type galaxies is in favour of soft-core DM profiles in galaxies of this kind. On the other hand, the observed young ages of nuclear clusters provide evidence supporting cuspy-core profiles. in conclusion, both the soft- and cuspy-core DM density profiles are suitable to relevant dwarf galaxies based on comparisons with observations.
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Yin, Yike, Shiyu Cao, Huancheng Fu, Xueying Fan, Jingfei Xiong, Qiuyue Huang, Yu Liu, et al. "A noncanonical role of NOD-like receptor NLRP14 in PGCLC differentiation and spermatogenesis." Proceedings of the National Academy of Sciences 117, no. 36 (August 24, 2020): 22237–48. http://dx.doi.org/10.1073/pnas.2005533117.
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NOD-like receptors (NLRs) are traditionally recognized as major inflammasome components. The role of NLRs in germ cell differentiation and reproduction is not known. Here, we identified the gonad-specific Nlrp14 as a pivotal regulator in primordial germ cell-like cell (PGCLC) differentiation in vitro. Physiologically, knock out of Nlrp14 resulted in reproductive failure in both female and male mice. In adult male mice, Nlrp14 knockout (KO) inhibited differentiation of spermatogonial stem cells (SSCs) and meiosis, resulting in trapped SSCs in early stages, severe oligozoospermia, and sperm abnormality. Mechanistically, NLRP14 promoted spermatogenesis by recruiting a chaperone cofactor, BAG2, to bind with HSPA2 and form the NLRP14−HSPA2−BAG2 complex, which strongly inhibited ChIP-mediated HSPA2 polyubiquitination and promoted its nuclear translocation. Finally, loss of HSPA2 protection and BAG2 recruitment by NLRP14 was confirmed in a human nonsense germline variant associated with male sterility. Together, our data highlight a unique proteasome-mediated, noncanonical function of NLRP14 in PGCLC differentiation and spermatogenesis, providing mechanistic insights of gonad-specific NLRs in mammalian germline development.
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Xie, Xuan, Rafael Nóbrega, and Martin Pšenička. "Spermatogonial Stem Cells in Fish: Characterization, Isolation, Enrichment, and Recent Advances of In Vitro Culture Systems." Biomolecules 10, no. 4 (April 22, 2020): 644. http://dx.doi.org/10.3390/biom10040644.
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Spermatogenesis is a continuous and dynamic developmental process, in which a single diploid spermatogonial stem cell (SSC) proliferates and differentiates to form a mature spermatozoon. Herein, we summarize the accumulated knowledge of SSCs and their distribution in the testes of teleosts. We also reviewed the primary endocrine and paracrine influence on spermatogonium self-renewal vs. differentiation in fish. To provide insight into techniques and research related to SSCs, we review available protocols and advances in enriching undifferentiated spermatogonia based on their unique physiochemical and biochemical properties, such as size, density, and differential expression of specific surface markers. We summarize in vitro germ cell culture conditions developed to maintain proliferation and survival of spermatogonia in selected fish species. In traditional culture systems, sera and feeder cells were considered to be essential for SSC self-renewal, in contrast to recently developed systems with well-defined media and growth factors to induce either SSC self-renewal or differentiation in long-term cultures. The establishment of a germ cell culture contributes to efficient SSC propagation in rare, endangered, or commercially cultured fish species for use in biotechnological manipulation, such as cryopreservation and transplantation. Finally, we discuss organ culture and three-dimensional models for in vitro investigation of fish spermatogenesis.
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Zhu, Jinbin, Liang Wang, Limin Xiao, and Guangjun Qin. "uDMA: An Efficient User-Level DMA for NVMe SSDs." Applied Sciences 13, no. 2 (January 10, 2023): 960. http://dx.doi.org/10.3390/app13020960.
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The Non-Volatile Memory Express (NVMe) SSD provides high I/O performance for current computer systems, and direct memory access (DMA) is the critical enabling mechanism for direct I/O. However, the lengthy I/O stack becomes a new bottleneck that degrades the potential of NVMe SSD. This paper reveals that existing user-level DMA introduces additional overhead for pinning memory used by DMA from the user space. Moreover, it cannot adapt to I/O requests of different data sizes. This paper proposes an efficient and dynamically adaptive user-level DMA (uDMA) mechanism that can adapt to I/O requests for different data sizes and lighten the I/O software stack by amortizing per-request latency. The critical component of uDMA is the pinned memory pool, which avoids frequently pinning new memory blocks by reusing allocated and pinned memory blocks. In addition, it effectively connects the discrete pinned memory blocks by the scatter/gather lists, improving the utilization of the pinned memory pool. Compared with the latest user-level DMA method, uDMA has an improvement of at least 17% under various data sizes.
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Thiageswaran, Shiama, Heather Steele, Anna Laura Voigt, and Ina Dobrinski. "A Role for Exchange of Extracellular Vesicles in Porcine Spermatogonial Co-Culture." International Journal of Molecular Sciences 23, no. 9 (April 20, 2022): 4535. http://dx.doi.org/10.3390/ijms23094535.
Full textAbstract:
Spermatogonial stem cells (SSCs) provide the basis for lifelong male fertility through self-renewal and differentiation. Prepubertal male cancer patients may be rendered infertile by gonadotoxic chemotherapy and, unlike sexually mature men, cannot store sperm. Alternatively, testicular biopsies taken prior to treatment may be used to restore fertility in adulthood. Testicular SSC populations are limited, and in vitro culture systems are required to increase numbers of SSCs for treatment, demanding culture systems for SSC propagation. Using the pig as a non-rodent model, we developed culture systems to expand spermatogonia from immature testis tissue, comparing different feeders (Sertoli cells, peritubular myoid cells (PMCs) and pig fetal fibroblasts (PFFs)). Spermatogonia co-cultured with Sertoli cells, PMCs and PFFs had comparable rates of proliferation and apoptosis. To elucidate the mechanism behind the beneficial nature of feeder layers, we investigated the role of extracellular vesicles in crosstalk between spermatogonia and feeder cells. Sertoli cell-released exosomes are incorporated by spermatogonia, and inhibition of exosomal release reduces spermatogonial proliferation. Together, these results show that PMCs, PFFs and Sertoli cells promote spermatogonial proliferation in co-culture, with exosomal exchange representing one possible mechanism. Further characterization of exosomal cargo may ultimately allow the development of feeder-free culture systems for clinical use.
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Hudson, M. K., R. E. Denton, M. R. Lessard, E. G. Miftakhova, and R. R. Anderson. "A study of Pc-5 ULF oscillations." Annales Geophysicae 22, no. 1 (January 1, 2004): 289–302. http://dx.doi.org/10.5194/angeo-22-289-2004.
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Abstract. A study of Pc-5 magnetic pulsations using data from the Combined Release and Radiation Effects Satellite (CRRES) was carried out. Three-component dynamic magnetic field spectrograms have been used to survey ULF pulsation activity for the approximate fourteen month lifetime of CRRES. Two-hour panels of dynamic spectra were examined to find events which fall into two basic categories: 1) toroidal modes (fundamental and harmonic resonances) and 2) poloidal modes, which include compressional oscillations. The occurence rates were determined as a function of L value and local time. The main result is a comparable probability of occurence of toroidal mode oscillations on the dawn and dusk sides of the magnetosphere inside geosynchronous orbit, while poloidal mode oscillations occur predominantly along the dusk side, consistent with high azimuthal mode number excitation by ring current ions. Pc-5 pulsations following Storm Sudden Commencements (SSCs) were examined separately. The spatial distribution of modes for the SSC events was consistent with the statistical study for the lifetime of CRRES. The toroidal fundamental (and harmonic) resonances are the dominant mode seen on the dawn-side of the magnetosphere following SSCs. Power is mixed in all three components. In the 21 dusk side SSC events there were only a few examples of purely compressional (two) or radial (one) power in the CRRES study, a few more examples of purely toroidal modes (six), with all three components predominant in about half (ten) of the events. Key words. Magnetospheric physics (MHD waves and instabilities; magnetospheric configuration and dynamics) – Space plasma physics (waves and instabilities)
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Cammarata, Marcello, Piervincenzo Rizzo, Debaditya Dutta, and Hoon Sohn. "Application of principal component analysis and wavelet transform to fatigue crack detection in waveguides." Smart Structures and Systems 6, no. 4 (May 25, 2010): 349–62. http://dx.doi.org/10.12989/sss.2010.6.4.349.
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Weber, Andreas. "Cognition as expression: On the autopoietic foundations of an aesthetic theory of nature." Sign Systems Studies 29, no. 1 (December 31, 2001): 153–68. http://dx.doi.org/10.12697/sss.2001.29.1.10.
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This paper attempts to put forward an aesthetic theory of nature based on a biosemiotic description of the living, which in turn is derived from an autopoietic theory of organism (p. Varela). An autopoietic system's reaction to material constraints is the unfolding of a dimension of meaning. In the outward Gestalt of autopoietic systems, meaning appears as fonn, and as such it reveals itself in a sensually graspable manner. The mode of being of organisms has an irreducible aesthetic side in which this mode of being becomes visible. Nature thus displays a kind of transparency of its own functioning: in a nondiscursive way organisms show traces of their conditio vitae through their material self-presentation. Living beings hence always show a basic level of expressiveness as a necessary component of their organic mode of being. This is called the ecstatic dimension of nature (G. Böhme, R. Corrington). Autopoiesis in its full consequence then amounts to a view reminding of Paracelsus' idea of the signatura rerum (c. Glacken, H. Böhme): nature is transparent, not because it is organized digitally as a linguistic text or code, but rather because it displays analogically the kind of intentionality engendered by autopoiesis. Nature as a whole, as «living fonn" (S. Langer), is a symbol for organic intentionality. The most fundamental meaning of nature protection thus is to guarantee the «real presence" of our soul.