bluuebunny/crossref_metadata_2025 huggingface dataset:
Energy, Exergy, and Exergoeconomic Analysis of Solar Thermal Power Plant Hybrid with Designed PCM Storage
Authors: Fani Maryam , Norouzi Nima , Ramezani Molood
Published: September 2020

The tendency of renewable energies is one of the consequences of changing attitudes towards global energy issues. As a result, solar energy, which is the leader among renewable energies based on availability and potential, plays a crucial role in thoroughly filing global needs. Significant problems with the solar thermal power plants (STPP) are the operation time, which is limited by daylight and is approximately half of the power plants with fossil fuels, and the capital cost. In the present study, a new suggested sketch of adding latent heat storage (LHS) filled with commercial phase change material (PCM) to a 500-kW STPP case study has been investigated. Solar system details and irradiation amounts for a case study, including total and beam radiation have been determined. Also, the theoretical energetic and exergetic analysis of adding PCM storage to STTP is conducted, which showed a 19% improvement in the exergetic efficiency of the power plant to reach 30%. Besides, an optimized storage tank and appropriate PCM material have been investigated and selected concerning the practical limitations of the case study. By designing a new cycle, the LHS will be charged during daylight and will be discharged at night, doubling power plant operation time up to 2500[Formula: see text]h. Finally, exergoeconomic survey of STPP hybrid with PCM storage was carried out using Engineering Equation Solver (EES) program with genetic algorithm (GA) for three different scenarios, based on eight decision variables, which led us to decrease final product cost (electricity) in optimized scenario up to 30% compared to base case scenario from 28.99 to 20.27 $/kWh for the case study. Also, a comparison is made to demonstrate the effectiveness of the proposed new cycle on 250, 500, 1000, and 2000 kW STTPs.
Expanding the toolbox for dating basaltic lava sequences:
40
Ar–
39
Ar dating of silicic volcanic glass from interbeds
Authors: Cogliati Simone , Sherlock Sarah C. , Halton Alison M. , Ebinghaus Alena , Kelley Simon P. , Jolley David W. , Barry Tiffany L.
Published: September 2020

40
Ar–
39
Ar dating of glass shards from silicic tuffs of the Ellensburg Formation (NW, USA) interbedding basaltic lavas yielded accurate, precise, reproducible plateau and isochron ages that are within error at the 2σ level. The age-spectra have flat plateaus and the inverse isochrons have atmospheric
40
Ar/
36
Ar at the 2σ level. Ages of 12.00 ± 0.24, 11.37 ± 0.15, 10.67 ± 0.21 and 10.70 ± 0.18 Ma are consistent with the stratigraphy of four of the dated layers; the age of 10.77 ± 0.18 Ma for a fifth layer is at odds with the stratigraphy. This discrepancy arises due to the effect of glass alteration that induced K- and Ar-loss. There is no evidence of excess
40
Ar or
39
Ar recoil. The new ages indirectly constrain the timing of eruption of the lavas above and below the ash beds. This demonstrates that volcanic glass from interbeds can be used as an additional tool for indirectly dating basaltic lava sequences, which is independent of the lavas and complementary to other materials. Considering the numerous studies in which volcanic glass failed to provide reliable
40
Ar–
39
Ar ages, additional and supportive constraints are still needed to assess the validity of the ages from glass shards.

Supplementary material
: A1 – sample location, stratigraphic position and depositional environments; A2 – electron microprobe information with calibration and sample data; A3 – Ar isotopic data of blanks and samples, data reduction software, J values, criteria for age calculation and images of age spectra and inverse isochrons are available at
https://doi.org/10.6084/m9.figshare.c.5077705
The Law, the Computer, and the Mind
Authors: Press Gil
Published: September 2020

2011 marked the 50th anniversary of the first educational program on computer law, sponsored by the Joint Committee on Continuing Professional Education of the American Law Institute and the American Bar Association (ALI-ABA). In 1971 at an ACM conference, Roy Freed and six colleagues founded the Computer Law Association (CLA), an international bar association (renamed later as the International Technology Law Association).
The Rock Stars of eLearning: An interview with Reuben Tozman
Authors: Raymer Rick
Published: September 2020

Leadership and vision are characteristics of most influential people, and Reuben Tozman has these qualities in spades.
The New Learners
Authors: Layton-James Laura
Published: September 2020

Society has changed considerably over the last 50 years or so with considerable shifts in lifestyle. There is no longer a traditional family, a traditional employee, or a traditional student. In her new book, Tracey Wilen-Daugenti explores these changes and how technology can and is helping education adapt to meet the needs of today's society.
Raising the Bar: An interview with Carol Russell
Authors: Tracey Ryan
Published: September 2020

College students are tech savvy, and they want to use their mobile devices to enhance their learning experience. How should institutions and instructors respond? Dr. Carol Russell of the University of Western Sydney (UWS) in Australia has some thoughts and her answers may surprise you.
Gamification, Education and E-learning: An interview with Andrzej Marczewski
Authors: Bozkurt Aras
Published: September 2020

In this interview from Aras Bozkurt, one of the leading gamification experts, Andrzej Marczewski, discusses the definition of gamification, its impact on and its application in e-learning, and some insights about the future of the gamification.
Enriching Social Presence through Research and Practice
Authors: Yontz Elaine
Published: September 2020

'Social Presence in Online Learning: Multiple Perspectives on Practice and Research,' examines social presence through three lenses: as technologically facilitated, as learners' perceptions, and as a critical literacy. Whiteside, Dikkers, and Swan have edited an extremely useful volume that combines reviews of research with practical suggestions. The book makes a convincing case for the importance of social presence considerations in online course design.
Using Flipgrid to Increase Students' Connectedness in an Online Class
Authors: Bartlett Michelle
Published: September 2020

Flipgrid, a free video discussion forum tool, increases students' perceptions of connectedness in the online classroom. Video discussion forums embedded in an online course can be used in many ways to connect instructors to students, and students to their peers. Embedding a tool that brings voice, tone, and body language to the online classroom strengthens connectedness and can increase civility.
#teachingwithtwitter: Tweeting to foster online engagement and learning
Authors: Honig Catherine
Published: September 2020

Research on teaching with Twitter points to a variety of educational benefits to engagement and learning. Tweeting encourages a backchannel discussion of class topics and activities, and it has the potential to expand learning in interesting ways. A constellation of emerging best practices offers helpful guidance for instructors and paves the way for effective implementation in both online and face-to-face courses.
Using 'Code Words': A simple gamification technique to guide students to instructor personalized resources
Authors: Steele John , Humphrey Samia
Published: September 2020

The purpose of this article is to offer ideas using a simple gamification technique of the ?code word? to connect students to vital classroom content and or personalized instructor materials. However, there is no value in this material if instructors are unable to guide their students to it. Gamification can provide ways to engage students in seeking out these beneficial resources that can help them be successful in the course.
Optimizing Feedback Delivery with Text-Expanders
Authors: Moore Heather
Published: September 2020

This article presents strategies to optimize usage of text-expanders. Online instructors need to deliver high-quality feedback on a high volume of assignments in a short span of time, yet high volume means that feedback delivery can be a repetitive task as students make similar mistakes. When repetitive tasks are combined with time pressure, feedback quality degradation may result. Text-expanders are one possible tool to maintain quality while improving time efficiency.
Using Texting Tools to Reinforce Communication in the Online Classroom
Authors: Evans Shelley , Rhodes Marny , Anderton Alecia
Published: September 2020

Texting tools are useful communication tools used by higher education instructors to send short messages to students or guardians. The tool can also be a vehicle for enhancing student engagement and communication by sending reminders, words of encouragement, and other announcements. Some texting tools are accessible to students with disabilities thanks to the voice-to-text feature, highlighted in this article. Challenges to using texting tools are addressed and best practices for implementation are described.
Standing Out: Online content marketing for online programs
Authors: Cross Ted , Polk Laura
Published: September 2020

As digital education becomes more accepted by learners and more institutions offer programs online, getting the word out about programs has become increasingly challenging. This paper offers a case study and recommendations for online content marketing of online programs.
Using Screen Recording Platforms to Increase Instructor Presence in an Online Classroom
Authors: Kelly Seanan , Banaszewski Charles
Published: September 2020

Recent advances such as video and audio conferencing, online real-time chat and instant messaging features have created synchronous learning opportunities in online classrooms. Use of screen recording tools specifically, provide the ability to make short recordings, which provide a quick and personal way to respond to individuals or groups. Additionally, when utilized for feedback purposes, screen recordings enhance instructor presence in the classroom, provide one-to-one, teacher-student exchanges reducing the virtual distance between instructors and students.
Conference Reports
Authors: Pérez Jorge A
Published: September 2020

In this installment of the conference report column, Mihaela Rozman, Valeria de Paiva, Amy Felty, and Ursula Martin report on the Second Workshop of Women in Logic (WiL2018), which took place in Oxford on July 8th, 2018 co-located with LICS.
Examining Police Agencies’ Dialogic Accounting Practices in Facebook Conversations
Authors: Wu Qunfang , Huang Yun
Published: September 2020

Police agencies have been posting regularly on Facebook and trying to use this social media platform for building community policing. However, little is known about how the public comments to police agencies’ posts and how the agencies further reply to public comments on Facebook. Addressing these questions helps us understand police agencies’ practices of using Facebook for supporting dialogic accounting, i.e., responding to multiple viewpoints, on this social media platform. In this work, we collected 29,928 Facebook posts of 43 municipal police agencies in the U.S. and 628,098 public comments to those agencies’ posts, as well as all replies to the public comments (including replies from other public users and the agencies). We find that the agencies only replied to 907 (0.1%) public comments. Our findings show that (1) the public’s comments varied in diverse topics, but the agencies mainly replied to those comments that were
Seeking
information; (2) the agencies replied quickly when
Acknowledging
positive public comments; and (3) the agencies often ignored negative comments. We also discuss design implications for social media platforms to support better dialogic accounting practices.
The European IST ExPlanTech project
Authors: Koumpis Adamantios
Published: September 2020

Hands-on adoption of a multi-agent production planning technology in the manufacturing industry.
Beyond numbers
Authors: Ubiquity staff
Published: September 2020

Martha Amram on the current economics of technology investment.
Genesis of an anthill
Authors: Andersen Espen
Published: September 2020

The future belongs to small, connected devices that will wirelessly allow the user -- and the technology -- to self-organize, creating something smart out of many small and simple nodes and connections.
Lessons For Life
Authors: Preece Jenny
Published: September 2020

Children require engaging, carefully written and well-targeted material, with easy access to additional details. They need tools that enable them to create, discuss, respond, and analyze news and stories. Easy access to safe forums, blogs, and moderated chats could make a difference.
Five Technological Considerations When Choosing an E-Learning Solution
Authors: Kapp Karl M.
Published: September 2020

This article looks at different e-learning technologies and briefly discusses the pros and cons of each. It then explains five technology characteristics that you should look for when selecting an e-learning solution, Regardless of whether your focus is academic or corporate.
The aeffability of knowledge management
Authors: Downes Stephen
Published: September 2020

The Aeffability of Knowledge Management [1] The challenge of knowledge management, and hence of online learning, is to make it work with the complexity and richness of actual human communication.
visuos
Authors: Lango Clemens
Published: September 2020

Modular, integrated software could help knowledge workers keep track and make sense of abundant information by narrowing the cognitive load.
The logical structure of the memory resource in the SYMBOL-2R computer
Authors: Richards Hamilton , Zingg Roy J.
Published: September 2020

As has been reported elsewhere
1-5
, the SYMBOL-2R computer system's basic design premises included the following:

1. implementation of a user-oriented high-level programming language directly in hardware;

2. provision of interactive computing service for as many as 31 independent user terminals simultaneously;

3. incorporation of a virtual-memory system, using a small core memory to buffer a large paging drum.

In this paper, we shall touch only peripherally on the last two of these premises; our chief concern here is to describe those aspects of SYMBOL's memory structure that impinge upon the first premise, namely, direct high-level language implementation.
Program execution in the SYMBOL 2R computer
Authors: Hutchison P. C. , Ethington K.
Published: September 2020

The direct hardware implementation of the SYMBOL Programming Language (SPL) is highly dependent on an unusually powerful Central Processor(CP). This paper describes the principal features of the CP's operations in executing SPL programs.
Introduction to the SYMBOL 2R programming language
Authors: Richards Hamilton , Wright Charles
Published: September 2020

The SYMBOL programming language (SPL) is not only an important feature of the SYMBOL 2R Computer System, but also was the starting point for the design of the system. SPL was designed as a general-purpose, higher-level programming language. After the language design was completed, the hardware of the SYMBOL computer was then designed to provide a hardware implementation of the language.

This paper is intended primarily to provide a general overview of SPL as context for the companion papers (1,3,6). The reader is referred to (5) for a complete description of SPL, to (2) for a discussion of the design decisions involved in the creation of SPL, and to (4) for an overview of the entire SYMBOL project.
Design of an aerospace computer for direct HOL execution
Authors: Nielsen William C.
Published: September 2020

This paper presents an overview of a study, performed during 1971 and 1972, to design a computer architecture capable of executing a higher-order aerospace programming language directly—without the aid of a compiler or interpreter. The prime motivation for developing such a machine is to reduce system costs, for while hardware logic is becoming much cheaper, software is consuming a greater proportion of total system costs. A tremendous potential savings can be obtained by designing computer hardware that is oriented to aiding the programmer rather than to simplifying the computer designer's job.

In this three-phase study, the first phase, preliminary to the actual design, analyzed direct execution tradeoffs for a number of languages. The languages examined were FORTRAN, ALGOL, PL/I, APL, JOVIAL, and SPL. In the second phase, the functional design was produced for a direct-execution system for a subset of Space Programming Language (SPL)/Mark IV. In the third phase, the performance of that system was evaluated by comparing it to a conventional architecture. The study successfully demonstrated that a higher-order aerospace language computer is feasible and efficient.
Implementation of a tagged architecture for block structured languages
Authors: McMahan L. N. , Feustel E. A.
Published: September 2020

This paper describes the implementation of a tagged architecture for a block structured language. First a model for the environment of block structured languages based on an extension to MADCAP VI is developed. Then the implementation of the model in hardware is described.
The internal machine
Authors: Welin Andrew M.
Published: September 2020

Two results are presented in this paper: an enlargement of the concept of machine languages and a way to design computers based on an inner machine oriented toward interpretation of machine languages in general. In Part I we discuss attributes of “directly interpretable languages” and processing mechanisms related to their interpretation. “Sequential extraction” allows an instruction to be of arbitrary form, while “linear decoding” allows us to organize the interpreting routines into structures. This leads to powerful machine language level capabilities. Using the mechanisms of Part I, we build in Part II the case for the “internal machine” approach to computer design. The internal machine (unlike microprocessors) is not oriented towards low level (gate, register) manipulation of data, but its operations reflect elementary actions related to the process of interpretation. The advantages of the internal machine include simplicity, programming interface (as opposed to the interface offered by microprocessors), and the ability to handle directly interpretable languages.

One can choose among many architectures for the internal machine. An organization based on the execution stack is suggested as the most general solution. The essential “general purpose” organizations of the internal machines lend themselves to extensions and specializations which provide extra efficient handling of specific subprocesses related to interpretation.
A report on the value of some advanced high level language operators on current sequential computers
Authors: Schutte Lawrence J.
Published: September 2020

Recent advances in programming languages have sometimes drastically altered program structure as in the Reduction Languages of Backus (3) or produced less drastic but nonetheless dramatic effects like the elimination of the “goto” statement in an increasing number of “structured” programming languages (4). Now waiting in the wings are demands for topologically simpler program structures which will ease code optimization problems, increase programmer productivity, and aid automatic verification of program correctness. In these respects, perhaps the most advanced high-level programming language yet developed is Aiken Dynamic Algebra (ADA), the younger sister of APL (5, 6, 7). Boyce (8) has already shown the improved efficiency of ADA on pipeline and parallel machines, but his results for ADA in a sequential environment were inconclusive. This study reports the comparison of a sequential ADA implementation with the standard instruction sets of two existing sequential machine designs, the IBM 1130 and the IBM 360. Addition of 150 microinstructions allowed simultaneously a 5 to 35% decrease in execution time and a 5 to 40% decrease in the storage requirements for code to implement identical algorithms.
The PL/EXUS language and virtual machine
Authors: Sitton Gary A. , Kendrick Thomas A. , Carrick A. Gil
Published: September 2020

This paper describes a high level general purpose language which evolved from another high level systems programming language. As well, the compiler, pseudocode, and virtual machine are discussed in some detail. The new language is a powerful PL/1 dialect, as is its parent language, XPL
1
. PL/EXUS (
P
rogramming
L
anguage/
E
xtended
X
PL
U
sers'
S
uperset), was created to satisfy a particular set of needs. A highly machine independent, mobile, compact, and powerful programming system was needed for implementation of programs to manipulate medical record data on modestly configured minicomputers. The primary extensions to XPL were semantic and dictated the structure of a host virtual machine. Because of the number of different data types and implicit mixed mode conversion rules, the virtual machine has a tagged data architecture. This results in a small instruction set of under 64 operators and thus enables powerful, implicit, run time instruction interpretation. The PL/EXUS virtual machine has a basic eight bit word size. Its virtual memory capabilities require only a fraction of the program and data to be in real memory at a time. The ability to specify storage space for most data types results in parsimonious space allocation in spite of the presence of tag words (one eight-bit byte per identifier or constant). Some instructions were specifically created to allow the compiler to “peep-hole” (i.e., locally) optimize generated pseudocode programs. The compiler itself is written in XPL, which permits self-compilation and makes possible its execution on the virtual machine or a simulated (interpretive) version of it.
Transient software fault tolerance through recovery
Authors: Saha Goutam Kumar
Published: September 2020

A low-cost and effective solution for developing transient fault tolerant application software based on a single-version program
An Interview with Thomas Kalil
Authors: Ubiquity staff
Published: September 2020

From the White House to Berkeley, Thomas Kalil has worked on shaping the national agenda for science and technology research initiatives. Kalil, President Clinton's former science and technology advisor, now holds a similar post at the University of California, Berkeley, where he helps develop new research initiatives and increase UC Berkeley's role in shaping the national agenda.
Calm technologies in a multimedia world
Authors: Tugui Alexandru
Published: September 2020

In an ideal world, computers will blend into the landscape, will inform but not overburden you with information, and make you aware of them only when you need them.
Status and Targets for Polymer-Based Solid-State Batteries for Electric Vehicle Applications
Authors: Kim Hong-Keun , Srinivasan Venkat
Published: September 2020

There is growing interest in the development of Li-metal-based solid state batteries, driven by their promise in improving the energy density to satisfy electric vehicle requirements. In this contribution, we examine the status of Solid polymer electrolytes (SPEs) based solid state batteries for electric vehicle applications using a continuum scale mathematical model. We examine LiFePO4 (LFP) cathode/lithium metal anode batteries containing three different electrolytes, namely (1) a liquid electrolyte, (2) the polystyrene-b-poly(ethylene oxide) (SEO) block copolymer electrolyte, and (3) a single-ion conducting (SIC) block copolymer electrolyte, with the liquid electrolyte serving as the baseline for the comparison. By using an optimization procedure, we assemble “virtual” batteries to identify the optimal design that maximizes energy density while allowing the power requirements of electric vehicles (EVs) to be satisfied. Results show the present status of different SPEs are still below what is considered acceptable and further improvements are needed to achieve electric vehicle targets. The optimization studies conducted here show that for low transference number electrolytes (∼0.2) the conductivity target is 5 × 10−3 S cm−1, while for a unity transference number electrolyte this target decreases to 4 × 10−4 S cm−1. These targets provide guidance for polymer synthesis researchers to develop better polymers for use in EVs.
X-ray Absorption Spectroscopy of Silicon Carbide Thin Films Improved by Nitrogen for All-Silicon Solar Cells
Authors: Khatami Zahra , Bleczewski Lyndia , Neville John J. , Mascher Peter
Published: September 2020

Synchrotron-based experiments in combination with optical measurements were used to explore the potential of a photovoltaic material based on silicon carbonitride (SiCN) thin films, in particular for the use in space solar cells. The large bandgap, SiCN films were fabricated using electron cyclotron resonance plasma-enhanced chemical vapour deposition (ECR-PECVD) followed by low-temperature annealing processes. X-ray absorption near edge structure (XANES) with excitations at the carbon, nitrogen, and silicon K-edges verifies that the presence of nitrogen tends to disrupt Si–C networks. This results in the enhancement of light absorption and bandgap widening, which is desirable for front emitters in all-silicon tandem solar cells. The ternary structure of SiCN allows bandgap engineering and tuning of the light absorption and refractive index through careful design of the composition. XANES showed that the thermal annealing at a medium temperature (500 °C) using N2 ambient promoted the formation of Si–Si and C–N sp2 bonds before disappearing in higher annealing temperatures. In our opinion unlocking the potential of robust SiC mixed with nitrogen in SiCN matrix has appeal in radiation-resistant solar cells, where it can serve as the top emitter layer in all-silicon tandem solar cells and at the same time benefits the antireflection properties.
High Removal Rate Cobalt Slurry with Glutathione on Chemical Mechanical Polishing in Alkaline Slurry
Authors: Xu Aoxue , Feng Daohuan , Wang Weilei , Liu Weili , Song Zhitang
Published: September 2020

As the technology node reaches 10 nm and below, cobalt has great potential as a barrier layer for copper interconnects and even as a new generation of interconnect materials. In this paper, the effect of double complexation of L-Aspartic Acid (L-Asp) and glutathione (GSH) on cobalt chemical mechanical polishing (CMP) is investigated in H2O2 based alkaline slurry. The results reveal that L-Asp and GSH can respectively complex cobalt ions to form a water-soluble complexes and cobalt removal rate increased more than ten times to 2500 Å min−1. Through electrochemical tests and X-ray photoelectron spectroscopy (XPS) experiments to explore the removal mechanism of cobalt. The analysis results indicate that the increase in the removal rate of cobalt is due to the formation of Co-L-Asp complexes and Co(II)-GSH complexes and Co(III)-GSH complexes on the cobalt surface. In addition, adding GSH on the basis of L-Asp and H2O2 can effectively reduce the potential difference between copper and cobalt.
MnDPDP: Contrast Agent for Imaging and Protection of Viable Tissue
Authors: Jynge Per , Skjold Arne M. , Falkmer Ursula , Andersson Rolf G. G. , Seland John G. , Bruvold Morten , Blomlie Viggo , Eidsaunet Willy , Karlsson Jan O. G.
Published: September 2020

The semistable chelate manganese (Mn) dipyridoxyl diphosphate (MnDPDP, mangafodipir), previously used as an intravenous (i.v.) contrast agent (Teslascan™, GE Healthcare) for Mn-ion-enhanced MRI (MEMRI), should be reappraised for clinical use but now as a diagnostic drug with cytoprotective properties. Approved for imaging of the liver and pancreas, MnDPDP enhances contrast also in other targets such as the heart, kidney, glandular tissue, and potentially retina and brain. Transmetallation releases paramagnetic Mn2+for cellular uptake in competition with calcium (Ca2+), and intracellular (IC) macromolecular Mn2+adducts lower myocardialT1to midway between native values and values obtained with gadolinium (Gd3+). What is essential is thatT1mapping and, to a lesser degree,T1weighted imaging enable quantification of viability at a cellular or even molecular level. IC Mn2+retention for hours provides delayed imaging as another advantage. Examples in humans include quantitative imaging of cardiomyocyte remodeling and of Ca2+channel activity, capabilities beyond the scope of Gd3+based or native MRI. In addition, MnDPDP and the metabolite Mn dipyridoxyl diethyl-diamine (MnPLED) act as catalytic antioxidants enabling prevention and treatment of oxidative stress caused by tissue injury and inflammation. Tested applications in humans include protection of normal cells during chemotherapy of cancer and, potentially, of ischemic tissues during reperfusion. Theragnostic use combining therapy with delayed imaging remains to be explored. This review updates MnDPDP and its clinical potential with emphasis on the working mode of an exquisite chelate in the diagnosis of heart disease and in the treatment of oxidative stress.
Clinical Presentations and Outcomes of Retinoblastoma Patients in relation to the Advent of New Multimodal Treatments: A 12-Year Report from Single Tertiary Referral Institute in Thailand
Authors: Rojanaporn Duangnate , Attaseth Taweevat , Dieosuthichat Wimwipa , Leelawongs Kitikul , Pakakasama Samart , Anurathapan Usanarat , Chanthanaphak Ekachat , Singhara Na Ayudhaya Sirintara , Aroonroch Rangsima , Hongeng Suradej
Published: September 2020

Purpose. To investigate the clinical presentations and outcomes of retinoblastoma in relation to the advent of new multimodal treatments in Thailand. Patients and Methods. Retrospective case series. We evaluated the clinical presentation, staging, details of treatment, and treatment outcomes of retinoblastoma patients who were treated at Ramathibodi Hospital, Bangkok, Thailand, between January 1, 2007, and December 31, 2018. The log-rank test was used to explore clinical characteristics and treatment modalities that affected globe salvage and survival curves. Results. This study included 124 eyes of 81 patients with retinoblastoma. Forty-three patients (53.1%) had bilateral retinoblastoma. The median age at diagnosis was 8 months (range, 1–48 months). Of 124 eyes, 9 eyes (7.3%) had extraocular retinoblastoma and 115 eyes (92.7%) had intraocular retinoblastoma, which were classified by the International Classification of Retinoblastoma (ICRB) as group A, 4 eyes (3.5%); group B, 19 eyes (16.5%); group C, 6 eyes (5.2%); group D, 31 eyes (27%); and group E, 56 eyes (47.8%). Treatment included systemic chemotherapy, intra-arterial chemotherapy, ruthenium-106 plaque brachytherapy, external beam radiation therapy, cryotherapy, transpupillary thermotherapy, subtenon chemotherapy, and intravitreal chemotherapy. At the median follow-up period of 38.4 months (range, 0.2–148.2 months), the overall globe salvage rate of intraocular retinoblastoma was 51.7%. For unilateral retinoblastoma, globe salvage rate was 37.5% (group B, 100%; group C, 100%; group D, 50%; and group E, 18.8%). For bilateral intraocular retinoblastoma, the globe salvage rate was 57.8% (group A, 100 %; group B, 94.4%; group C, 100%; group D, 64.7%; and group E, 28.2%). The overall survival rate was 93.8%. Conclusions. Recent advanced treatment modalities have improved the probability of globe salvage. However, enucleation remains an important life-saving intervention in many advanced cases.
Comparison of the Antiaging and Protective Properties of Plants from the Apiaceae Family
Authors: Zofia Nizioł-Łukaszewska , Martyna Zagórska-Dziok , Aleksandra Ziemlewska , Tomasz Bujak
Published: September 2020

Plant materials play a very significant role as components of products being used both for medicinal and cosmetic purposes. Due to the high content of active substances, they can play an important role as extracts with antioxidant, regenerative, and antiaging properties. The skin aging process depends on various pathological and physiological processes, among which the degradation of extracellular matrix biomolecules such as collagen and elastin, which significantly affect the maintenance of good skin condition, is very important. The secondary metabolites and plant extracts may have collagenase and elastase inhibitory activity. This activity is mainly due to the high content of a wide range of various biologically active compounds, such as polyphenols, which include, among others, flavonoids, phenolic acids, tocopherols, and tannins. The work involved a comprehensive assessment of the plant from Apiaceae family such as Meum athamanticum L., Centella asiatica L., and Aegopodium podagraria L. extract as a multifunctional raw material. During study antioxidant properties, phenolic compounds and flavonoids content, effect on collagenase and elastase enzyme activity (antiaging effect), cytotoxic properties on skin cells (keratinocytes and fibroblasts), and cell migration capacity were analyzed. It has been shown that the highest antioxidant capacity can be observed for the extract of herb of Aegopodium podagraria L. When the concentration reached 5% all tested extracts had a positive effect on the cell proliferation of both keratinocytes and fibroblasts. It turned out that the most promising inhibitor of collagenase and elastase enzymes was the extract from Aegopodium podagraria, which inhibits the activity of both enzymes by over 70% in the concentration of 5% positively affecting the condition of skin cells.
Evaluating Executive Functions in Patients with Juvenile Myoclonic Epilepsy Using Frontal Assessment Battery
Authors: Sanjari Moghaddam Hossein , Doost Hoseini Masoud , Khaleghi Mohammad Reza , Tafakhori Abbas , Dolatshahi Mahsa , Pourmirbabaei Shayan , Agah Elmira , Meshkat Shakila , Aghamollaii Vajiheh
Published: September 2020

Objective. In this study, we aimed to evaluate the executive profile of juvenile myoclonic epilepsy (JME) patients using the Frontal Assessment Battery (FAB) as a bedside screening tool and investigate its association with seizure proximity, family history of epilepsy, and polytherapy/monotherapy with antiepileptic drugs (AEDs). Background. JME patients have deficits in various aspects of executive functions. FAB has proved to be a useful tool for evaluating executive functions in clinical settings. Methods. Thirty-one JME patients and 110 healthy controls (HCs) were enrolled in this study. The participants were assessed using six subsets of FAB, including conceptualization, mental flexibility, motor programming, sensitivity to interference, inhibitory control, and environmental autonomy. Results. Compared to HCs, JME patients showed lower scores in conceptualization, mental flexibility, programming, sensitivity to interference, and total FAB. The number of AEDs (polytherapy versus monotherapy) and duration of time since the last seizure had no significant effect on FAB scores in JME patients. We found significant associations between disease duration and conceptualization, mental flexibility, inhibitory control, and total FAB score only in JME patients with recent seizure. Finally, receiver operating characteristic (ROC) analysis showed area under the curve (AUC) of 0.971 (95% confidence interval (CI): 0.947–0.994) for FAB total score, 0.933 for conceptualization (95% CI: 0.973-894), and 0.836 for mental flexibility (95% CI: 0.921-751). Conclusions. In summary, JME patients had deficits in different aspects of executive functions. FAB is a useful clinical tool for evaluation of executive functions in JME patients.
Study on the Instability Characteristics and Bolt Support in Deep Mining Roadways Based on the Surrounding Rock Stability Index: Example of Pansan Coal Mine
Authors: Chang Jucai , He Kai , Yin Zhiqiang , Li Wanfeng , Li Shihui , Pang Dongdong
Published: September 2020

In view of the influence of mining stress on the stability of the surrounding rock of inclined roof mining roadways in deep mines, the surrounding rock stability index is defined and solved based on the rock strength criterion and the stress distribution. The mining roadway of the 17102(3) working face of the Pansan Coal Mine is used as the engineering background and example. The surrounding rock’ stabilities under the conditions of no support and bolt support are analyzed according to the surrounding rock’s stability index and the deformation data. The results show that the areas of low wall and high wall instability are 1.68 m2 and 2.12 m2, respectively, and the low wall is more stable than the high wall; the areas of the roof and floor instability are 0.33 m2 and 0.35 m2, respectively, and the roof and floor are more stable than the two sides. During mining, the area of instability greatly increases at first, then decreases to 0, and reaches a maximum value at the peak of the abutment pressure. The stability of the surrounding rock decreases first and then increases. Compared with the end anchoring bolt support, the full‐length anchoring bolt support reduces the area of instability to a greater extent, and the full‐length anchoring bolt support effect is better. The surrounding rock in the end anchoring zone and the full‐length anchoring zone began to deform significantly at 200 m and 150 m from the working face, respectively. This indicates that the control effect of the full‐length anchoring bolt support is better and verifies the rationality of the surrounding rock stability index to describe the instability characteristics. This research method can provide a theoretical reference for analysis of the stability characteristics and support design of different cross‐section roadways.
Numerical Study of Damage to Rock Surrounding an Underground Coal Roadway Excavation
Authors: Wei Jiangbo , Wang Shuangming , Zhao Zhou , Li Delu , Guo Lipeng
Published: September 2020

In coal mines, underground roadways are required to transport coal and personnel. Such tunnels can become unstable and hazardous. This study simulates deformation and damage in the rock surrounding a shallow coal seam roadway using particle flow code. A numerical model of particle flow in the surrounding rock was constructed based on field survey and drilling data. Microcharacteristic indices, including stress, displacement, and microcrack fields, were used to study deformation and damage characteristics and mechanisms in the surrounding rocks. The results show that the stress within the rock changed gradually from a vertical stress to a circumferential stress pattern. Stress release led to self‐stabilizing diamond‐shaped and X‐shaped tensile stress distribution patterns after the excavation of the roadway. Cracking increased and eventually formed cut‐through cracks as the concentrated stress transferred to greater depths at the sides, forming shear and triangular‐shaped failure regions. Overall, the roof and floor were relatively stable, whereas the sidewalls gradually failed. These results provide a reference for the control of rock surrounding roadways in coal mines.
A Study on Cut Blasting with Large Diameter Charges in Hard Rock Roadways
Authors: Cheng Bing , Wang Haibo , Zong Qi , Xu Ying , Wang MengXiang , Zheng Qiangqiang , Li Chengjie
Published: September 2020

To overcome the problems of poor cutting effects in hard rock roadways, a cut blasting technique with large diameter charges was developed; that is, the cut holes employ 50 mm diameter blast holes and 45 mm diameter explosive sticks, while the other holes adopt 42 mm diameter blast holes and 35 mm diameter explosive sticks. First, the effect of charge diameter on damage range and cut cavity formation was analyzed. Next, simulation of wedge cut for different charge diameters was conducted to reveal the stress wave developments and compare the stress field intensities. Finally, field tests were conducted to verify the viability of this technique. The results indicate that large diameter charges can increase the damage range around cut holes to improve the fragmentation degree of the rock mass in the cut cavity and significantly enhance the cavity formation power to better expel the rock mass fragments. The stress wave evolution of wedge cut was visualized using numerical simulations, which confirmed that the use of large diameter charges in cut holes increases the stress field intensity in the cut cavity and hence increases the damage degree of the rock mass. In this study, the use of a large diameter charge for cut blasting increased the average footage by 0.30 m, and the average utilization rate of blast holes increased by 12.5%. Therefore, the cutting effects in hard rock roadways can be improved by using large diameter charges, which increase the blasting footage and the utilization rate of blast holes.
A New Scalable and Expandable Access Control Model for Distributed Database Systems in Data Security
Authors: Guclu Mehmet , Bakir Cigdem , Hakkoymaz Veli
Published: September 2020

Access control models are an important tool developed for securing today’s data systems. Institutions use the access control models specifically to define who their employees are, what they can do, which resources they can reach, and which processes they can perform and use them to manage the whole process. This is a very hard and costly process for institutions with distributed database systems. However, access control models cannot be implemented in a qualified way due to the fact that the conditions for defining users’ demands to reach resources distributed on different servers, one of which is consequentially bound to the other, the verification and authorization of those user demands, and being able to monitor the actions of the users cannot be configured in an efficient way all the time. With our model suggested in this study, the aim is to automatically calculate the permissions and access levels of all users defined in the distributed database systems for the objects, and, in this way, we will reach a more efficient decision as to which objects the users can access while preventing their access to the information they do not need. Our proposed model in this study has been applied to real life data clusters from organizations providing health and education services and a public service. With the proposed model, all models have been run on servers sharing resources in a private network. The performance of the proposed model has been compared to that of traditional access models. It was confirmed that the proposed model presented an access control model providing more accurate access level results as well as being scalable to many distributed database systems.
Granular Bentonite Preparation and Effect of Granulation Behavior on Hydromechanical Properties of Bentonite
Authors: Tan Yunzhi , Li Hui , Sun De’an , Ming Huajun
Published: September 2020

Compacted bentonite is regarded as a suitable buffer/backfill material in a high‐level radioactive waste disposal repository due to its low permeability, high swelling, and strong adsorption capacity, but the bentonite powder is difficult to compact to a high density only by increasing the compaction energy. Hence, a proposal is made to improve the compactness of bentonite by changing its grain size distribution. To obtain bentonite granules with different sizes, a granulation method is proposed in this paper, in which bentonite powders experience the processes of wetting and drying into plate bentonites, which are then crushed into granules. Furthermore, in this paper, the hydromechanical behavior of granular bentonite is evaluated to verify the feasibility of the method for preparing granules. For this purpose, the granular and original bentonite powder with similar grain sizes were prepared; then, various laboratory tests, including measurements of free swelling ratio, swelling pressure, water retention capacity, and compactness, were carried out. The test results show that the free swelling ratio, swelling pressure, permeability coefficient, and water retention capacity of granular bentonite are almost similar to those of original bentonite, and after compaction, the maximum dry densities of granular and original bentonites are 1.72 and 1.64 g/cm3 at the optimum moisture content (20%) and the energy consumption was reduced by 38% with the void ratio decreased from 1.30 to 0.8 compared with the original bentonite. It indicates that, compared with the original bentonite, the hydromechanical behavior of granular bentonites changed a little, but its compaction performance has been significantly improved. To investigate the differences in pore size distributions of granular bentonite and original bentonite, MIP and NA tests were performed on samples produced with the wetting‐drying agglomerate method, and the results show that the pores with a size of 10.0 μm almost disappear and the pores mainly exist with a size of approximately 1.0 μm. It can be verified that preparing granules by the wetting‐drying agglomeration method is feasible, the granulation process has little effect on the hydromechanical properties of bentonite, and after granulation, not only the compactness is improved but also the energy consumption is saved.
The Integrated Hydropower Sustainability Assessment in Tajikistan: A Case Study of Rogun Hydropower Plant
Authors: Xu Zhao , Niu Yumin , Liang Yangze , Li Zhigang , Iftikhor Atoev
Published: September 2020

Tajikistan has formulated the strategy to rejuvenate the country through hydropower. The Rogun hydropower plant (HPP) is designed as the highest hydropower station, while its sustainability is also questioned due to a lack of comprehensive sustainability evaluation. Considering that the external environment of Rogun HPP is complex and changeable, its sustainable performance will be fragile and inconstant. To comprehensively assess the sustainable performance, an integrated evaluation framework, covering the current and dynamic sustainable performance, is urgently established. Therefore, this paper firstly explored the hydropower sustainability assessment indicators which can conform to Tajikistan’s situations and further examined the current sustainable performance of Rogun HPP. The case study found that Rogun HPP’s current financial viability, involuntary resettlement, the measures to prevent corruption, and information disclosure were seriously deficient. The SWOT analysis indicated the external factors, such as the Belt and Road Initiative, improving business environment, and easing geopolitical disputes, can eliminate weaknesses and improve the sustainable performance of Rogun HPP. At the same time, tight fiscal allocations and economic downturns will have negative influences on the sustainable performance. The integrated evaluation tool established in this paper can not only evaluate the current sustainable performance but also consider the impact of external factors on sustainable performance from a dynamic perspective. This paper contributes to the current knowledge system by establishing the hydropower sustainability assessment system which is suitable for Tajikistan’s conditions. Moreover, the results are informative for the decision‐makers to have a better understanding of Rogun HPP’s current strengths and weaknesses, valuable opportunities, and potential threats.