RETRACTED: Investigation on the Mechanical Properties of Fiber Reinforced Recycled Concrete

This article has been retracted: please see Civil Engineering Journal policies:(https://www.civilejournal.org/index.php/cej/about/editorialPolicies).This article has been retracted at the request of the Editor-in-Chief. Violation of rules: submitting articles without approval of all coauthors

Supreme audit court of auditors' insights on operational audit challenges

Operational audit plays an important role on managing governmental budget. It helps control government spending and other important budgetary issues. This paper presents an empirical study to find out the possible barriers on implementing operational audit. The proposed study distributes some questionnaires among supreme audit court of auditors and analyzes the questions. The results indicate that many governmental organizations are not strongly committed to rules and regulations. There are not sufficient standards on auditing programs and many governmental agencies do not even use operational budgeting system since they are not aware of the benefits of such system. There are some of the most important challenges of having operational budgeting and paper suggests some guidelines for having better regulation on removing the main barriers

Modeling and control of dissolved oxygen concentration in the fermentation of Glucose to Gluconic Acid

Fermentation systems are often highly nonlinear, with poorly understood dynamic behaviour of the reactor. In this work, mathematical modeling of the fermentation process based on aeration rate control was performed in a semi-batch airlift loop bioreactor. The bioconversion of glucose to gluconic acid by the Aspergillus niger strain was considered in an oxygen consuming system in the liquid phase. The proper kinetic model for the bioconversion of glucose to gluconic acid was investigated using experimental data from a 40 dm3 reactor. Kinetic parameter estimation was used from the literature. The model was validated by experimental data and was compared with the Monod kinetic model. The comparison showed that the Contois kinetic model was in a better agreement with the experimental data of dissolved oxygen concentration (DO) than the Monod kinetic model. An optimal substrate-to-microorganism concentration ratio of 55 was suggested by applying the model, which led to achieving the maximum conversion of glucose to gluconic acid. The conventional PID controller with fixed parameters obtained from the Ziegler-Nichols tuning method was used to control the dissolved oxygen concentration at a constant level of 2 mg/dm3, which was important for microorganism survival and growth

ON THE BUCKLING AND VIBRATIONAL RESPONSE OF CARBON NANOTUBES WITH SPIRAL DEFORMATION

Perfect and spiral models of carbon nanotubes (CNTs) have been simulated based on the finite element method and their vibrational and buckling behavior has been investigated. In order to evaluate their natural frequency and critical buckling load, computational tests have been conducted. It has been concluded that the existence of any geometrical modification in the configuration of perfect CNTs results in a remarkable reduction in the natural frequency and critical buckling load of CNTs. It has been also revealed that the analytical solutions are in good agreement with the finite element simulation results in the cases of perfect and spiral CNTs

Assume-Guarantee Reinforcement Learning

We present a modular approach to \emph{reinforcement learning} (RL) in environments consisting of simpler components evolving in parallel. A monolithic view of such modular environments may be prohibitively large to learn, or may require unrealizable communication between the components in the form of a centralized controller. Our proposed approach is based on the assume-guarantee paradigm where the optimal control for the individual components is synthesized in isolation by making \emph{assumptions} about the behaviors of neighboring components, and providing \emph{guarantees} about their own behavior. We express these \emph{assume-guarantee contracts} as regular languages and provide automatic translations to scalar rewards to be used in RL. By combining local probabilities of satisfaction for each component, we provide a lower bound on the probability of satisfaction of the complete system. By solving a Markov game for each component, RL can produce a controller for each component that maximizes this lower bound. The controller utilizes the information it receives through communication, observations, and any knowledge of a coarse model of other agents. We experimentally demonstrate the efficiency of the proposed approach on a variety of case studies.Comment: This is the extended version of the paper accepted in the SRRAI Special Track at the Conference on Artificial Intelligence (AAAI-24

PV-hosting-capacity enhancement and power-quality improvement through multiobjective reconfiguration of harmonic-polluted distribution systems

The current steps toward the implementation of carbon–neutral electrical energy systems lead to high levels of PV penetration especially in residential sectors. However, there are many limitations in the integration of extra PV generation units in modern distribution systems. Hence, supplementary actions are needed for providing the capability of hosting high levels of PV units in future grids. In this study, the application of Distribution System Reconfiguration (DSR) is examined in order to increase PV Hosting Capacity (PVHC) of a harmonically polluted distribution system. However, bringing several services together, DSR is studied in a multiobjective framework to improve the voltage profile and decrease the total energy loss as well as improving the PVHC. Moreover, probabilistic demand scenarios are included in this study through applying different combinations of linear and nonlinear load-levels to provide a more precise assessment of the objectives. Finally, a solution strategy is proposed for the presented multiobjective problem based on the implementation of the Non-dominated Sorting Genetic Algorithm II (NSGA-II) and fuzzy decision-making method. The proposed framework is then applied to modified 33-bus and 69-bus distribution systems in presence of nonlinear loads. According to the results, applying the proposed methodology for DSR could successfully increase the PVHC of the harmonic-polluted grid as well as providing voltage profile stabilization and a considerable decrease of the energy loss in the system.Peer reviewe

Probabilistic Planning of Virtually-Hybrid Harmonic Filters in Modern Distribution Systems

Peer reviewe

Global, regional, and national burden of colorectal cancer and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Funding: F Carvalho and E Fernandes acknowledge support from Fundação para a Ciência e a Tecnologia, I.P. (FCT), in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy i4HB; FCT/MCTES through the project UIDB/50006/2020. J Conde acknowledges the European Research Council Starting Grant (ERC-StG-2019-848325). V M Costa acknowledges the grant SFRH/BHD/110001/2015, received by Portuguese national funds through Fundação para a Ciência e Tecnologia (FCT), IP, under the Norma Transitória DL57/2016/CP1334/CT0006.proofepub_ahead_of_prin

State of the climate in 2018

In 2018, the dominant greenhouse gases released into Earth’s atmosphere—carbon dioxide, methane, and nitrous oxide—continued their increase. The annual global average carbon dioxide concentration at Earth’s surface was 407.4 ± 0.1 ppm, the highest in the modern instrumental record and in ice core records dating back 800 000 years. Combined, greenhouse gases and several halogenated gases contribute just over 3 W m−2 to radiative forcing and represent a nearly 43% increase since 1990. Carbon dioxide is responsible for about 65% of this radiative forcing. With a weak La Niña in early 2018 transitioning to a weak El Niño by the year’s end, the global surface (land and ocean) temperature was the fourth highest on record, with only 2015 through 2017 being warmer. Several European countries reported record high annual temperatures. There were also more high, and fewer low, temperature extremes than in nearly all of the 68-year extremes record. Madagascar recorded a record daily temperature of 40.5°C in Morondava in March, while South Korea set its record high of 41.0°C in August in Hongcheon. Nawabshah, Pakistan, recorded its highest temperature of 50.2°C, which may be a new daily world record for April. Globally, the annual lower troposphere temperature was third to seventh highest, depending on the dataset analyzed. The lower stratospheric temperature was approximately fifth lowest. The 2018 Arctic land surface temperature was 1.2°C above the 1981–2010 average, tying for third highest in the 118-year record, following 2016 and 2017. June’s Arctic snow cover extent was almost half of what it was 35 years ago. Across Greenland, however, regional summer temperatures were generally below or near average. Additionally, a satellite survey of 47 glaciers in Greenland indicated a net increase in area for the first time since records began in 1999. Increasing permafrost temperatures were reported at most observation sites in the Arctic, with the overall increase of 0.1°–0.2°C between 2017 and 2018 being comparable to the highest rate of warming ever observed in the region. On 17 March, Arctic sea ice extent marked the second smallest annual maximum in the 38-year record, larger than only 2017. The minimum extent in 2018 was reached on 19 September and again on 23 September, tying 2008 and 2010 for the sixth lowest extent on record. The 23 September date tied 1997 as the latest sea ice minimum date on record. First-year ice now dominates the ice cover, comprising 77% of the March 2018 ice pack compared to 55% during the 1980s. Because thinner, younger ice is more vulnerable to melting out in summer, this shift in sea ice age has contributed to the decreasing trend in minimum ice extent. Regionally, Bering Sea ice extent was at record lows for almost the entire 2017/18 ice season. For the Antarctic continent as a whole, 2018 was warmer than average. On the highest points of the Antarctic Plateau, the automatic weather station Relay (74°S) broke or tied six monthly temperature records throughout the year, with August breaking its record by nearly 8°C. However, cool conditions in the western Bellingshausen Sea and Amundsen Sea sector contributed to a low melt season overall for 2017/18. High SSTs contributed to low summer sea ice extent in the Ross and Weddell Seas in 2018, underpinning the second lowest Antarctic summer minimum sea ice extent on record. Despite conducive conditions for its formation, the ozone hole at its maximum extent in September was near the 2000–18 mean, likely due to an ongoing slow decline in stratospheric chlorine monoxide concentration. Across the oceans, globally averaged SST decreased slightly since the record El Niño year of 2016 but was still far above the climatological mean. On average, SST is increasing at a rate of 0.10° ± 0.01°C decade−1 since 1950. The warming appeared largest in the tropical Indian Ocean and smallest in the North Pacific. The deeper ocean continues to warm year after year. For the seventh consecutive year, global annual mean sea level became the highest in the 26-year record, rising to 81 mm above the 1993 average. As anticipated in a warming climate, the hydrological cycle over the ocean is accelerating: dry regions are becoming drier and wet regions rainier. Closer to the equator, 95 named tropical storms were observed during 2018, well above the 1981–2010 average of 82. Eleven tropical cyclones reached Saffir–Simpson scale Category 5 intensity. North Atlantic Major Hurricane Michael’s landfall intensity of 140 kt was the fourth strongest for any continental U.S. hurricane landfall in the 168-year record. Michael caused more than 30 fatalities and $25 billion (U.S. dollars) in damages. In the western North Pacific, Super Typhoon Mangkhut led to 160 fatalities and$6 billion (U.S. dollars) in damages across the Philippines, Hong Kong, Macau, mainland China, Guam, and the Northern Mariana Islands. Tropical Storm Son-Tinh was responsible for 170 fatalities in Vietnam and Laos. Nearly all the islands of Micronesia experienced at least moderate impacts from various tropical cyclones. Across land, many areas around the globe received copious precipitation, notable at different time scales. Rodrigues and Réunion Island near southern Africa each reported their third wettest year on record. In Hawaii, 1262 mm precipitation at Waipā Gardens (Kauai) on 14–15 April set a new U.S. record for 24-h precipitation. In Brazil, the city of Belo Horizonte received nearly 75 mm of rain in just 20 minutes, nearly half its monthly average. Globally, fire activity during 2018 was the lowest since the start of the record in 1997, with a combined burned area of about 500 million hectares. This reinforced the long-term downward trend in fire emissions driven by changes in land use in frequently burning savannas. However, wildfires burned 3.5 million hectares across the United States, well above the 2000–10 average of 2.7 million hectares. Combined, U.S. wildfire damages for the 2017 and 2018 wildfire seasons exceeded $40 billion (U.S. dollars)