bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel hypothesis for how albatrosses optimize their flight physics in real-time: an extremum seeking model and control for dynamic soaring
Authors: Pokhrel Sameer , Eisa Sameh A
Published: November 2022

The albatross optimized flight maneuver—known as dynamic soaring—is nothing but a wonder of biology, physics, and engineering. By utilizing dynamic soaring, this fascinating bird can travel in the desired flight direction almost for free by harvesting energy from the wind. This phenomenon has been observed for centuries as evidenced by the writings of Leonardo da Vinci and Lord Rayleigh. Moreover, dynamic soaring biological inspiration has triggered a momentous interest among many communities of science and engineering, particularly aeronautical, control, and robotic engineering communities. That is, if dynamic soaring is mimicked, we will have arrived at a new class of unmanned aerial vehicles that are very energy-efficient during part (or the full) duration of their flight. Studying, modeling, and simulating dynamic soaring have been conducted in literature by mostly configuring dynamic soaring as an optimal control problem. Said configuration requires accurate dynamic system modeling of the albatross/mimicking-object, accurate wind profile models, and a defined mathematical formula of an objective function that aims at conserving energy and minimizing its dissipation; the solution then of such optimal control problem is the dynamic soaring trajectory taken—or to be taken—by the bird/mimicking-object. Furthermore, the decades-long optimal control configuration of the dynamic soaring problem resulted in non-real-time algorithms and control solutions, which may not be aligned well with the biological phenomenon itself; experimental observations of albatrosses indicate their ability to conduct dynamic soaring in real-time. Indeed, a functioning modeling and control framework for dynamic soaring that allows for a meaningful bio-mimicry of the albatross needs to be autonomous, real-time, stable, and capable of tolerating the absence of mathematical expressions of the wind profiles and the objective function—hypothetically similar to what the bird does. The qualifications of such modeling and control framework are the very same characteristics of the so-called extremum seeking systems. In this paper, we show that extremum seeking systems existing in control literature for decades are a natural characterization of the dynamic soaring problem. We propose an extremum seeking modeling and control framework for the dynamic soaring problem hypothesizing that the introduced framework captures more features of the biological phenomenon itself and allows for possible bio-mimicking of it. We provide and discuss the problem setup, design, and stability of the introduced framework. Our results, supported by simulations and comparison with optimal control methods of the literature, provide a proof of concept that the dynamic soaring phenomenon can be a natural expression of extremum seeking. Hence, dynamic soaring has the potential to be performed autonomously and in real-time with stability guarantees.
Socio-technical modelling of UK energy transition under three global SSPs, with implications for IAM scenarios
Authors: Freeman Rachel , Pye Steve
Published: November 2022

The potential for using findings from socio-technical energy transition (STET) models in integrated assessment models (IAMs) has been proposed by several authors. A STET simulation model called TEMPEST, which includes the influence of societal and political factors in the UK’s energy transition, is used to model three of the global shared socioeconomic pathways (SSPs) at the national level. The SSP narratives are interpreted as inputs to TEMPEST, which drive scenario simulations to reflect varying societal preferences for mitigation measures, the level of political support for energy transition, and future economic and population trends. SSP1 and SSP2 come close to meeting UK net zero targets in 2050 but SSP5 does not reach net zero before 2080. An estimate of the total societal, political, and economic cost of scenarios indicates that while SSP1 achieves the best emissions reductions it also has the highest total cost, and SSP2 achieves the best ratio between rate of emissions reductions and total cost. Feasibility appears to be highest for SSP2 since it is the least different to historical precedent. Current UK government energy strategy is closer to the narrative in SSP5, however, which has the highest total cost and exceeds an estimated carbon budget by 32%. Three key TEMPEST findings are recommended for use in IAMs: (i) the uncertainty in emissions savings due to variability in political and societal support for energy transition, (ii) the influence of negative societal pushback to policies in achievement of expected policy outcomes, and (iii) the combined influence on energy service demand of disposable income, public willingness to participate, and user impacts from measures.
Carbon footprint patterns of domestic migrants in China and 1.5 °C mitigation pathways
Authors: Wang Rui , Chen Guangwu , Wang Yafei , Feng Jiahao
Published: November 2022

Rural–urban migration and the growing carbon footprints (CFs) will challenge the world in keeping the global average-temperature increment below 1.5 °C compared to preindustrial levels. We first quantified the CFs of migrant consumption in 30 Chinese provinces in 2013 and 2015. An integrated approach was developed to match the Chinese multiregional input–output table with household survey data covering 200 000 migrant survey samples. Furthermore, we adopted the three shared socioeconomic pathways (SSPs) to explore the carbon budgets and trajectories of the migrants and permanent residents to align with the 1.5 °C climate target. The results suggest that the average migrant CFs ranged from 2.3 to 2.6 tCO2e per capita in 2015. To align with 1.5 °C pathways, the emissions of migrants should be held below 3.4 tCO2e per capita under the 12 SSPs–1.9 scenarios from 2020 and keep decreasing to net-zero before 2050. To ensure citizenry progress in improving well-being without overshooting dual carbon targets, high-emitting migrants need to reduce their emissions substantially.
Is hydrogen production through natural gas pyrolysis compatible with ambitious climate targets in the United States? A location-specific, time-resolved analysis
Authors: Keller Martin
Published: November 2022

Pyrolysis of natural gas to produce H2 and solid carbon through methane cracking can be characterized as a high-CH4, low-CO2 process. It results in low CO2 emissions because no direct CO2 is generated at the point of H2 generation if solid carbon is not combusted further. However, it results in high CH4 emissions because of its higher natural gas consumption compared to the direct use of natural gas and, thus, higher CH4 losses along the natural gas supply chain. Here, I analyzed whether this process can provide climate benefit in comparison to the direct, unabated utilization of natural gas and also in comparison with H2 produced from water electrolysis with grid electricity. To this end, Monte Carlo simulations of time-resolved and US state-specific emission profiles and their impact on mid-century global warming under different CH4 mitigation scenarios were conducted. It was found that the climate benefit of natural gas pyrolysis is highly dependent on plant location and the speed at which CH4 emissions can be abated. New York, Pennsylvania, and Ohio emerged as the most promising locations. This is because of their projected long reliance on natural gas for power generation, which renders electrolysis using grid electricity less attractive, as well as the relatively low estimate of current CH4 emissions from the natural gas supply chain. However, without fast action on CH4 emission mitigation, the climate benefit of natural gas pyrolysis is small or non-existent, irrespective of the plant location. Overall, the uncertainty in the relative climate benefit of natural gas pyrolysis was found to be large; however, this study developed an easy-to-adapt MS Excel/visual basic for applications (VBA) tool that can be updated as soon as more accurate data on CH4 emissions becomes available. Policymakers, businesspeople, and scholars can use this tool to estimate the climate impact within their own scenarios and locations.
A century of variations in extreme flow across Finnish rivers
Authors: Gohari Alireza , Jalali Shahrood Abolfazl , Ghadimi Sahand , Alborz Mohammadreza , Patro Epari Ritesh , Klöve Björn , Torabi Haghighi Ali
Published: November 2022

River flow in cold climates is known to be one of the hydrological systems most affected by climate change, playing a central role in the sustainability of downstream socio-ecological systems. Numerous studies on the temporal and spatial variations of streamflow characteristics have been done, and a comprehensive study on the variation of hydrologic extremes is becoming increasingly important. This study evaluated the long-running changes in the magnitude, time, and inter-annual variability of hydrologic extremes, including high and low flow in 16 major Finnish rivers. We applied four new hydrologic extreme indices for summer–winter low flow ratio, spring-absolute high flow ratio, time-to-peak index, and increasing rate index during the snowmelt period to analyze the spatiotemporal variations of extreme streamflow from 1911 to 2020. The most detected trends in flow regimes have started in the last six decades and become more severe from 1991 to 2020, which is likely to be dominated by anthropogenic global warming. The results also indicated that alteration of low pulses in most rivers was associated with an increase (decrease) in winter (summer) flows, suggesting the annual minimum flow in summer frequently contradicts natural hydrologic regimes in Arctic rivers. Southern Finland has experienced higher variations in extreme hydrology over the last century. A new low flow regime was detected for southern rivers, characterized by frequent annual minimum flow in summer instead of winter. Moreover, the annual maximum flow before/after spring dictated a new high-flow regime characterized by frequent double peak flows in this region.
How air pollution altered the association of meteorological exposures and the incidence of dengue fever
Authors: Ju Xu , Zhang Wangjian , Yimaer Wumitijiang , Lu Jianyun , Xiao Jianpeng , Qu Yanji , Wu Gonghua , Wu Wenjing , Zhang Yuqin , Chen Shirui , Lin Xiao , Wang Ying , Wang Xinran , Jiang Jie , Lin Ziqiang , Ma Xiaowei , Du Zhicheng , Hao Yuantao
Published: November 2022

Meteorological exposures are well-documented factors underlying the dengue pandemics, and air pollution was reported to have the potential to change the behaviors and health conditions of mosquitos. However, it remains unclear whether air pollution could modify the association of meteorological exposures and the incidence of dengue fever. We matched the dengue surveillance data with the meteorological and air pollution data collected from monitoring sites from 2015 through 2019 in Guangzhou area. We developed generalized additive models with Poisson distribution to regress the daily counts of dengue against four meteorological exposures, while controlling for pollution and normalized difference vegetation index to evaluate the risk ratio (RR) of dengue for each unit increase in different exposures. The interaction terms of meteorological exposures and air pollution were then included to assess the modification effect of different pollution on the associations. Daily dengue cases were nonlinearly associated with one-week cumulative temperature and precipitation, while not associated with humidity and wind speed. RRs were 1.07 (1.04, 1.11) and 0.95 (0.88, 1.03) for temperature below and above 27.1 °C, 0.97 (0.96, 0.98) and 1.05 (1.01, 1.08) for precipitation below and above 20.3 mm, respectively. For the modification effect, the RRs of low-temperature, wind speed on higher SO2days and low-precipitation on both higher PM2.5and SO2days were greater compared to the low-pollution days withPinteractionbeing 0.037, 0.030, 0.022 and 0.018. But the RRs of both high-temperature on higher SO2days and high-precipitation on higher PM2.5d were smaller withPinteractionbeing 0.001 and 0.043. Air pollution could alter the meteorology-dengue associations. The impact of low-temperature, low-precipitation and wind speed on dengue occurrence tended to increase on days with high SO2levels while the impact of high-temperature decreased. The impact of low-precipitation increased on high-PM2.5d while the impact of high-precipitation decreased.
Forests for forests: combining vegetation indices with solar-induced chlorophyll fluorescence in random forest models improves gross primary productivity prediction in the boreal forest
Authors: Pierrat Zoe Amie , Bortnik Jacob , Johnson Bruce , Barr Alan , Magney Troy , Bowling David R , Parazoo Nicholas , Frankenberg Christian , Seibt Ulli , Stutz Jochen
Published: November 2022

Remote sensing is a powerful tool for understanding and scaling measurements of plant carbon uptake via photosynthesis, gross primary productivity (GPP), across space and time. The success of remote sensing measurements can be attributed to their ability to capture valuable information on plant structure (physical) and function (physiological), both of which impact GPP. However, no single remote sensing measure provides a universal constraint on GPP and the relationships between remote sensing measurements and GPP are often site specific, thereby limiting broader usefulness and neglecting important nuances in these signals. Improvements must be made in how we connect remotely sensed measurements to GPP, particularly in boreal ecosystems which have been traditionally challenging to study with remote sensing. In this paper we improve GPP prediction by using random forest models as a quantitative framework that incorporates physical and physiological information provided by solar-induced fluorescence (SIF) and vegetation indices (VIs). We analyze 2.5 years of tower-based remote sensing data (SIF and VIs) across two field locations at the northern and southern ends of the North American boreal forest. We find (a) remotely sensed products contain information relevant for understanding GPP dynamics, (b) random forest models capture quantitative SIF, GPP, and light availability relationships, and (c) combining SIF and VIs in a random forest model outperforms traditional parameterizations of GPP based on SIF alone. Our new method for predicting GPP based on SIF and VIs improves our ability to quantify terrestrial carbon exchange in boreal ecosystems and has the potential for applications in other biomes.
Eigenstates of two-level systems in a single-mode quantum field: from quantum Rabi model to N-atom Dicke model in the Coulomb gauge
Authors: Leonau A U , San Nguyen Quang , Ulyanenkov A P , Skoromnik O D , Feranchuk I D
Published: November 2022

In the present paper we show that the Hamiltonian describing the resonant interaction of N two-level systems with a single-mode electromagnetic quantum field in the Coulomb gauge can be diagonalized with a high degree of accuracy using a simple basis set of states. This allows one to find an analytical approximation for the eigenvectors and eigenvalues of the system, which interpolates the numerical solution in a broad range of the coupling constant values. For the first time, we show that the energy spectrum of Dicke model (DM) as a function of N (with

N
≫
1

) satisfies the simple scaling relation. In addition, the introduced basis states provide a regular way of calculating the corrections and estimating the convergence to the exact numerical solution. Analytical approximations and numerical results describing the energy spectrum are valid for both quantum Rabi model (N = 1) and DM for

N
⩾
2

atoms.
Algebraic Bethe ansatz for Q-operators of the open XXX Heisenberg chain with arbitrary spin
Authors: Frassek Rouven , Szécsényi István M
Published: November 2022

In this note we construct Q-operators for the spin s open Heisenberg XXX chain with diagonal boundaries in the framework of the quantum inverse scattering method. Following the algebraic Bethe ansatz we diagonalise the introduced Q-operators using the fundamental commutation relations. By acting on Bethe off-shell states and explicitly evaluating the trace in the auxiliary space we compute the eigenvalues of the Q-operators in terms of Bethe roots and show that the unwanted terms vanish if the Bethe equations are satisfied.
Ways to study changes in pedestrians’ behaviour in the artificially lit urban outdoor environment
Authors: Ingi Dmitrii , Bhusal Pramod , Pinho Paulo , Kyttä Marketta , Parker Martin
Published: November 2022

Lighting technologies have been rapidly developing in recent years together with the advancement in digital and connected technologies. Nevertheless, while achieving quantitative goals with the help of technical developments, there is always a need to correlate them with their impacts on users’ experience. This paper focuses on the changes in human behaviour whilst walking under an artificially lit outdoor environment. A systematic literature search was conducted from which three groups of a pedestrians’ behaviour were identified, namely walking (including activity levels and walking patterns), microscopic mobility (including walking speed, gait characteristics and use of walkway space) and gaze behaviour. An additional round of a literature search was done for each of the group mentioned above. Final set of the articles consisted of 41, 13 and 12 papers for walking, microscopic mobility behaviour and gaze behaviour subgroups respectively. The existing knowledge on possible changes in pedestrian behaviour caused by various artificial lighting settings was summarized. In addition, the methods to gather data about these changes applied in the selected papers were reviewed, and the perspectives for video-based analysis and online public participation geographic information system methodologies were discussed.
Describing the characteristics of light field in architectural spaces using spherical harmonic function
Authors: Yanagawa Kazunori , Fujihira Ayane , Yamaguchi Hideki , Yoshizawa Nozomu
Published: November 2022

The direction, density, and diffusivity of light are important indicators of spatial characteristics in describing a three-dimensional light environment. Mury presented a method for describing, measuring, and visualizing the structure of light fields using spherical harmonics in terms of changes in the density and direction of light in three-dimensional space. We extended this study by using higher-order spherical harmonics, which would represent more diverse characteristics of the light environment. We also quantitatively described the light environment as numerical values and investigated the correspondence between these numerical values and human perceptual quantities. As a result, we confirmed that there is a certain degree of correspondence between the “complexity” quantified by the spherical harmonic and the “complexity” perceived by people when observing real space.
The Appearances of Daylight – an educational method for studying daylight
Authors: Grønlund L
Published: November 2022

The central theme is daylight. In other words, seeing and sensing it, registering it through photographs and drawing the tangible conditions that form the framework for the appearances of daylight. Basically, it is about practising the ability to see differences – to see the differences in the daylight and thus heighten an awareness of how to choose to design with daylight in architecture. In educating architects, we are keenly aware of encouraging students to develop an awareness of the importance and effects of daylight. This paper will examine how the experience of daylight through a specific qualitative method can provide students with new knowledge through a phenological approach: gaining knowledge by studying the daylight in the home of each student where they live their daily lives, perhaps seeing the daylight or overlooking it. Their home becomes a laboratory for studying and documenting daylight through different formats and using different tools. There is a need to develop new teaching methods that can give students insight and tools for seeing daylight, founded on a belief that through this experience and knowledge they can design architecture with nuanced, diverse experiences of daylight. In a sustainable perspective, robust aesthetic sustainability must begin with the qualities of space, of which daylight is one of the most significant elements.
In-situ evaluation of high-performance glazing based on illuminance and glare
Authors: Karmann Caroline , Wienold Jan , Kostro André , Florio Pietro , Schüler Andreas , Scartezzini Jean-Louis , Andersen Marilyne
Published: November 2022

High-technology glazing panes are designed to meet the need for natural light, while optimizing key functions such as reducing solar heat gain in spaces and/or redirecting daylight to the rear of the spaces. However, the actual performance in terms of both illumination and glare protection of these glazing systems is often unknown. This study aims to compare the visual comfort performance of four complex fenestration systems by means of point-in-time measurements under real sky conditions and for different seasons. The tested systems included: two glazing types with embedded seasonal solar protection, namely, MicroShade™ and Coolshade™, one prototype of daylight redirecting glazing with embedded micro-mirrors (GEMM), and one clear glazing. We conducted our tests in side-by-side nearly identical spaces in the NEST building in Dübendorf, Switzerland. Results showed a higher daylight provision for clear and daylight redirecting glazing. Discomfort glare assessment from daylight showed that MicroShade™ was substantially more efficient at addressing glare due to sunlight for high sun angles when compared to Coolshade™. The performance of the GEMM prototype was highly dependent on the glazing pane used and one pane provided a promising performance when it comes to mitigating glare risks for high sun positions. However, none of the systems were able to provide an adequate glare protection for lower sun positions. The performed measurements provide a basis for the calibration of simulation models.
Identifying Nurses’ Perception of a Lighting Installation in a Newly Built Hospital
Authors: Schledermann Kathrine , Bjørner Thomas , Mullins Michael , Hansen Torben
Published: November 2022

Prior to the installation of new integrative lighting systems, perceived experiences by nurses of the existing lighting were collected as a baseline study through interviews at two newly built hospital units in Denmark. This paper addresses the advantages and barriers that the current lighting application presents for the nurses’ work-practice. The study found that ten out of twelve of the interviewed staff at the Neurointensive Care Unit (neuro-ICU) and Postanesthesia Care Unit (PACU) prefer to work in relatively dark conditions. The interviews revealed how light and darkness are perceived as important to the staff for entraining the circadian rhythm of the patients; this was manifested in their working routines. An identification and description of nurses’ experience will guide and inform future implementation of integrative lighting systems at neuro-ICU and PACU to ensure patients’ sleep quality and recovery, improve visual comfort for the staff, enhance the degree of perceived usefulness of the lighting systems and facilitate technology acceptance. The study concludes that there is a need for implementing differentiated lighting design for the different units and contexts in the hospital, in contrast to a ‘one-size fits-all’ lighting implementation.
Colour of reflected light: a determinant of sustainable spatial function
Authors: Bhatia M
Published: November 2022

According to the works of W.R. Ott, we are an ‘indoor species’, spending on an average, 87% of our time in closed environments [1]. Our long interaction with indoor surroundings, creates the need for such spaces to be sustainable, bringing factors affecting user behaviour and consequent usage patterns under the microscope. This is an empirical study investigating if reflected light carries a component of colour taken from pigmented surfaces and if this colour of reflected light has any influence on usability of a space and its user pattern. The study is conducted in domestic interior environments of a student housing in Stockholm under artificial light conditions that were static and constant. The period of study was limited to weekends to observe the user behaviour in conditions of free will. It is a comparative analysis between two dining spaces having identical architectural and lighting attributes, with colour of walls as the only change in the two study sets. There were two separate user groups of similar age groups, similar needs and similar time schedule. The study includes four stages of observation and data gathering by adopting qualitative and quantitative methodologies. The effects of colour on the perception of space and light and hence usability of the two spaces cannot be negated completely, even if more study is needed to prove the same. The results can be used to question the photometric instruments in their inability to detect such aspects of reflected light. This also helps to underline the need for involvement of a qualified lighting designer in the making of spaces from the beginning till the end for interpreting the effects of the interactions between light and pigmented surfaces. The findings may be considered a stimulus for developing a set of standards for colour and coloured reflected light in a given environment as a measurable parameter of light for sustained usage of indoor environments.
A review of lighting research in educational spaces
Authors: Angelaki S , Besenecker U , Danielsson C B
Published: November 2022

The present paper summarises tendencies related to research in lighting for school environments from 1980 to 2020. Methods and tools used to evaluate and analyse both daylight and electric lighting are presented. The studies in this literature review were grouped in four decades and are presented chronologically. The review suggests a shift from on-site evaluations in the early decades, both when using qualitative and quantitative research methods, to software-based research and analysis in more recent studies. during the past decade, there appears to be a general increase in both software and user-based techniques for evaluation and design of educational spaces. However, it is interesting that the lighting layout in classrooms does not show significant changes during the four decades since it follows the same grid pattern regardless of the changes in architectural, design and teaching tendencies.
Challenges in lighting education: a recommended practice
Authors: Scarazzato Paulo Sergio , da Silva Fonseca Matos Jéssica Cristine , França Ana Judite Galbiatti Limongi , Pavani Taísa Dóccosse
Published: November 2022

Although lighting is a theme usually loved by architects, there are few studies about appropriate pedagogical strategies focusing on its teaching in architectural undergraduate courses. This subject rarely is present in conferences, symposia, and similar events regarding architectural education. Due to historical mistakes, lighting education is often conducted in such courses with no link to the architectural design process. Regarding daylighting, it not always goes beyond solar geometry and insolation control, and electrical lighting is addressed to the discipline of electrical installations, strictly based on a calculation approach. It urges to present lighting to students as an integral and indissociable part of the architectural space itself. Also, it is essential to support a process of learning based on observation and laboratory experimentation. This paper discusses these issues and presents a pedagogical proposal favouring drawing with light, both daylighting and electrical lighting, since the first steps of the architectural design process. An electronic tool yet under development and destined to help in decision-making related to daylighting in the initial phases of design development is also presented. For a sustainable and safe future in a world in rapid transformations due to technological advances and pandemic events, lighting education deserves to be exhaustively studied by educators and architecture schools worldwide. Sharing knowledge in a network seems to be the best way for such an objective.
Lighting design for diversity: Learning from low-vision rehabilitation
Authors: Øien T B , Frandsen A K
Published: November 2022

Science understands and handles a phenomenon from different perspectives. Light is handled as daylight, artificial light, task light, and general light, as physics, electrical technology, or safety aids. However, as part of people’s everyday lives, the different characteristics of the phenomena fluxes and blend, as people’s needs and preferences to lighting differ across a day, in different situations, and not least across a lifetime. Current societal agendas as Leave No One Behind or the sustainable development goals, stress the need for a more holistic approach in design: For the built environment to support wellbeing, comfort, and quality of life, for all.

Disabilities have traditionally been defined in relation to abilities and the normal-bodied, with special aids for special needs, and special spaces for the ‘other’. Niches for the other is seen in the field of lighting as special solutions for visually impaired, and correspondingly, lighting is a niche in low-vision services, that has been guided by diagnostics and recommendations of specific lux levels. Thus, more holistic and interdisciplinary initiatives within low-vision rehabilitation that have explored the rehabilitative role of lighting as support of the visually impaired individual in their everyday life, show that individualizing and optimizing the individual’s domestic lighting can improve their quality of life. Can the findings from low-vision rehabilitation be translated into the field of lighting design, informing a qualitative approach, and work as an incubator for more diverse user perspectives?

The interactions of the low-vision consultants, visually impaired participants, and their domestic lighting, have been studied in a case study of the role of lighting in low-vision rehabilitation. Participatory observations of 15 consultations and interviews with 17 visually impaired participants form the basis for an analysis of the dynamic human environment interaction at stake, using the theoretical frameworks of affordance and usability. The analysis contributes to a more situated and dynamic understanding of light: The experience of light is context dependent, and lighting needs and preferences are diverging regardless of diagnosis but rather constituted by the dynamic interactions. Consequently, this calls for user involvement and a more diverse user perspective in design processes, which could support more useful designs.

This study implies a promising potential within the intersection of research paradigms and practice: Between quality of life, lighting quality, architectural quality, and user perspectives closer to people’s complex and changing needs and preferences.
Effect of Monsoonal Clustering for PM10 Concentration Prediction in Keningau, Sabah using Principal Component Analysis
Authors: Rumaling Muhammad Izzuddin , Chee F P , Chang J H W , Sentian J
Published: November 2022

Particulate matter (PM) has caught scientific attention in scientific research due to its harmful effect on human health. While prediction is essential for future development in Keningau, temporal clustering in Keningau has yet to be studied. Thus, this research aims to determine whether monsoonal clustering is required for meteorological and pollutant concentration data collected in Keningau. Missing data is first imputed using Nearest Neighbour Method (NNM). Then, wind direction and wind speed are converted into northern (Wy
) and eastern (Wx
) component of wind speed. Data is then temporal clustered based on monsoonal season (NEM, IM4, SWM, IM10). Both clustered and unclustered data are analysed using principal component (PC) analysis (PCA). The findings revealed that humidity in PC1 with average EV (explained variation) of 93.92 ± 0.52 contribute the most variation of PM10, followed by Wx
in PC2 with average EV of 3.51 ± 0.48. Regression analysis shows that humidity and PM10 are negatively moderate to strongly correlated except for IM4 (intermonsoon April), which may be due to dry climate during the season. As for Wx, it has weak correlation with PM10. This may be due to location of Keningau at western part of Crocker range. However, the spread of PM10 due to eastern wind causes weak to zero correlation. Due to consideration of dry climate as revealed by the findings from IM4 cluster, there is need for data collected by Keningau to be clustered by monsoon.
Enhanced Mechanical Properties Plaster of Paris with Addition of Rice Husk Fibers
Authors: Pirman Farmizan , Awang Asmahani
Published: November 2022

The incorporation of additives materials into gypsum alters water absorption and mechanical properties of the final products. Plaster of Paris were prepared by using conventional methods with distinctive sizes of rice husk fibers in the range of 38 μm, 63 μm, and 250 μm. The density, water absorption, porosity, and mechanical properties prior to compressive strength were examined. The density, water absorption, porosity, and mechanical properties of plaster lies in the range of 1.521 − 1.673 g/cm3, 25.107 − 33.989%, 40.196 − 53.295%, and 2.666 − 9.438 MPa, respectively. Variation in density, water absorption and porosity due to alteration in the distance among the gypsum crystals and void fractions. The incorporation of a small size of rice husk fibers of 38 μm weakened the compressive strength of plaster due to the impact of rice husk fibers as filler. Meanwhile, the incorporation of moderate size rice husk fibers in the range of 63 μm and 250 μm enhanced the compressive strength due to the contribution of rice husk fibers as reinforcement agent in the gypsum network.
Composition and surface morphology study of seaweed as biosorbent
Authors: Mingu Nazirah , Musa Noorsharmeza , Majid Mohd Hafiz Abd , Idris Juferi , Sarjadi Mohd Sani
Published: November 2022

In this study, based on the surface morphology study, it was found that the texture of the treated biosorbent has changed from smooth to dry and rough texture. It shows that the surface has been leached out during the biosorption process. The composition of Pb2+ and Al3+ ion metals was removed and determined using a biosorbent, red seaweed, Kappaphycus sp. The biosorbent was modified initially using 0.2 wt % formaldehyde to avoid organic leaching. The highest removal of Pb2+ and Al3+ were obtained at pH 3. Fourier Transform Infrared (FTIR) spectra showed that the functional groups involved for a metal binding in biosorbent from Kappaphycus sp. are carboxyl (1690-1760 cm-1), sulphate (1220-1260 cm-1) and hydroxyl (3200-3500 cm-1) group.
Interferometric evaluation of positioning error and position repeatability on CNCs
Authors: Stochioiu F P G , Stochioiu C , Rolea A M E , Gannam N
Published: November 2022

The interferometer is widely used for various applications concerning high precision distance and position measurements, especially for the calibration of numerically controlled machines. While the setup procedures of the interferometer may be provided by the manufacturer, some calibration procedures are well defined by the international standards. Since the operation of interferometers requires qualified personnel, some helpful hints for the novice users are to be presented in this paper. Even if the interferometer is highly recommended by international calibration standards, some factors are prone to intervene into the quality of results. This paper presents the experimental results for the evaluation of positioning accuracy and repeatability on Y axis of two vertical machining centres. The results show the high importance of environmental conditions compensation, the impact of time pauses during the measurement procedure and the implications of the increment of measuring target positions.
Progress of the RF negative hydrogen ion source for fusion at HUST
Authors: ZUO Chen , CHEN Peng , LI Zengshan , YANG Jinghan , SONG Fei , CHEN Dezhi
Published: November 2022

Huazhong University of Science and Technology has developed an experimental setup of a radio frequency (RF) driven negative hydrogen ion source, to investigate the physics of production and extraction of the H− ions for neutral beam injection in nuclear fusion reactors. The main design parameters of the ion source are: RF power ≤40 kW; extraction voltage ≤10 kV; accelerator voltage ≤20 kV. This paper gives an overview of the progress of the ion source with particular emphasis on some issues. The RF driver and source plasma are analyzed and optimized in terms of impedance matching, plasma characteristics and power coupling. In regard to the simulation analysis, a plasma model based on the particle-in-cell method and a beam trajectory model considering beam stripping loss are developed to investigate the plasma and negative ions transport inside the ion source. Furthermore, a collisional radiative model of H and H2 is built for plasma optical diagnosis.
Generation of atmospheric pressure air diffuse discharge plasma in oxygen enriched working gas with floating electrode
Authors: ZHANG Min , LIU Yunhu , LI Yao , LI Shuqi , YUAN Hao , LIANG Jianping , ZHOU Xiongfeng , YANG Dezheng
Published: November 2022

In this work, a floating electrode is employed to generate a stable large-area diffuse discharge plasma under an open oxygen-rich environment. The discharge image and the optical emission spectra of the N2(C-B),

N

2

+

(B-X), N2(B-A), and O(3p–3s, 777 nm) are measured to analyze the morphological and optical characteristics of the discharge. The effects of applied voltage, gas flow rate, and electrode gap on the reactive species, vibrational temperature and rotational temperature are investigated, and the discharge mode is discussed by simulating the electrostatic field before the breakdown. It is found that the changes of applied voltage and electrode gap causes the transition of the discharge modes among corona mode, diffuse discharge mode and spark mode. It is shown that the floating electrode can inhibit the transition from discharge to spark mode to a certain extent, which is conducive to maintaining the stability of discharge. As is vividly illustrated in this study, the increase of applied voltage or the decrease of electrode gap contributes to the generation of more active particles, such as N2(C) and

N

2

+

(B). Furthermore, the Joule heating effect becomes more evident with the increased applied voltage when the electrode gap is 15 and 20 mm. Moreover, as the applied voltage increases, the vibrational temperature increases at the electrode gap of 25 mm.
What is Gödel’s theorem?
Authors: Moore A. W.
Published: November 2022

The purpose of this chapter is to elucidate the content of Gödel’s theorem, which states that no axiomatization can determine the whole truth and nothing but the truth concerning arithmetic. Arithmetic is defined as the study of the natural numbers 0, 1, 2, … and the various operations that apply to them such as addition and multiplication. This prompts discussion of the idea of an algorithm—a mechanical step-by-step procedure that a computer could follow and that is guaranteed to produce a result after finitely many steps—since the operations in question are those that can be carried out by following an algorithm. An axiomatization is defined as a finite stock of basic principles and rules that can be used to prove statements. In these terms Gödel’s theorem states that no axiomatization of arithmetic can be both complete, in the sense that it can be used to prove every arithmetical truth, and sound, in the sense that it can’t be used to prove any arithmetical falsehood. Some common misconceptions of Gödel’s theorem are scotched. One of these is that the theorem establishes the existence of arithmetical truths that are absolutely unprovable; another is that it applies to all branches of mathematics, not just to arithmetic. Some other misconceptions are discussed that are much wilder and involve the bearing of the theorem on God and our understanding of the universe.
The key concepts involved in Gödel’s theorem
Authors: Moore A. W.
Published: November 2022

This chapter defines and explicates the key concepts involved in proving Gödel’s theorem. It begins with the concept of a formal language and the distinction between the logical vocabulary in such a language, which can be used in connection with any subject, and the non-logical vocabulary in it, which can be used only in connection with the language’s own subject. A statement in a formal language is then said to be a logical consequence of others when the language’s logical vocabulary guarantees that if they are all true, so is it. A theory is defined as a set of statements that includes all its own logical consequences. A theory is then said to be axiomatizable when it consists of the logical consequences of some set of axioms; sufficiently strong when it contains some core arithmetical truths; consistent when there is no statement in its language such that both the statement and its negation belong to the theory; and complete when there is no statement in its language such that neither the statement nor its negation belongs to the theory. Granted these definitions, Gödel’s theorem can be recast as follows: no theory can be sufficiently strong, consistent, complete, and axiomatizable. For each of these four conditions, an example is given of a theory that satisfies all but that one. Finally, a Gödel numbering is defined as an algorithmic assignment of natural numbers to the expressions in a formal language and to proofs involving them.
The diagonal proof of Gödel’s theorem
Authors: Moore A. W.
Published: November 2022

This chapter presents what is called the ‘diagonal’ proof of Gödel’s theorem. Two versions of the proof are given: a semantic version which proceeds on the assumption that any statement in any given formal language is either true or false; and a non-semantic version which dispenses with that assumption. Each proof begins by in effect assuming—contrary to what is to be proved—that there is a theory that is sufficiently strong, consistent, complete, and axiomatizable. An argument is given that, if there is such a theory, then there is an algorithm for telling whether any given statement belongs to it; and that, if there is such an algorithm, then, via a Gödel numbering, there is a set of natural numbers that is picked out by some expression in the language of the theory but that cannot be picked out by any expression in the language of the theory on pain of contradiction. Three features of the proof are highlighted: the connection that it establishes between axiomatizability and the existence of such an algorithm; the power that it shows that any such algorithm would have if it did exist; and the generous conception of sufficient strength on which it rests. The third of these raises a concern, namely that the conception is overgenerous. An assurance is given that this concern can be assuaged.
Living in the meantime
Authors: Williams Thomas
Published: November 2022

Although the satisfaction accomplished by the voluntary self-offering of the God-man is sufficient to heal the breach that human sin opened between God and humanity, it does not wipe out the effects of the sin of our first parents. Life in the meantime—life between satisfaction and ultimate consummation—is demanding, and Anselm speaks vividly of his awareness that we live on a knife-edge between heaven and hell. In his many letters of spiritual counsel he warns that it is much easier to fall than it is to ascend. We can do no good at all apart from God’s grace, but we can freely throw away that grace by willing something that is incompatible with it. Grace is simply God’s restoring an upright or just will: by free choice we can hold on to justice for the sake of justice itself, so that, far from being incompatible with free choice, grace gives our free choice its fullest scope. A just will, Anselm emphasizes, is one that wills what God wills it to will. Obedience—to God, to the just demands of our superiors—is crucial: it was one act of disobedience that banished our first parents from paradise. We are never secure from falling, but we are upheld by grace; and though Anselm never loses his sense that we are ‘halfway between fear and hope’, as he says in one of his prayers, hope does seem to get the final word.
Living with microbes
Authors: Douglas Angela E.
Published: November 2022

This chapter introduces the concept of microbes. It notes how all healthy animals and plants are inhabited by communities called microbiomes, which are generally regarded as an indication of health. In many animals, the most abundant microbial populations are housed in the gut, while the roots of plants are associated with large and diverse microbial communities. Although microbiomes generally promote the host of the animal or plant host, they can occasionally be deleterious. Strategies to study microbiomes include the use of laboratory animals, especially mice and fruit flies, that are deprived of their resident microorganisms and colonized with specific microorganisms.
Microbial therapies and healthy microbiomes
Authors: Douglas Angela E.
Published: November 2022

This chapter explores ongoing strategies to modify the microbiome of people and other animals, for improved health. The underlying rationale for these efforts comes from the evidence that industrial lifestyles have perturbed and impoverished microbiomes associated with both the gut and the skin. To date, the most successful microbial therapy is the application of faecal microbiome transplantation by colonoscopy for patients with infections of Clostridium difficile that are unresponsive to other therapies. Other interventions for improved health include microbial products taken by mouth in probiotic foods and prebiotic foods that promote the growth of beneficial microbes in the gut. There is also increasing interest in phage therapies that target specific pathogenic microbes.
Current Challenges With the Use of Test-Negative Designs for Modeling COVID-19 Vaccination and Outcomes
Authors: Shi Xu , Li Kendrick Qijun , Mukherjee Bhramar
Published: November 2022

The widespread testing for severe acute respiratory syndrome coronavirus 2 infection has facilitated the use of test-negative designs (TNDs) for modeling coronavirus disease 2019 (COVID-19) vaccination and outcomes. Despite the comprehensive literature on TND, the use of TND in COVID-19 studies is relatively new and calls for robust design and analysis to adapt to a rapidly changing and dynamically evolving pandemic and to account for changes in testing and reporting practices. In this commentary, we aim to draw the attention of researchers to COVID-specific challenges in using TND as we are analyzing data amassed over more than two years of the pandemic. We first review when and why TND works and general challenges in TND studies presented in the literature. We then discuss COVID-specific challenges which have not received adequate acknowledgment but may add to the risk of invalid conclusions in TND studies of COVID-19.