bluuebunny/crossref_metadata_2025_split huggingface dataset:
Classical Hamiltonian time crystals–general theory and simple examples
Authors: Dai Jin , Niemi Antti J , Peng Xubiao 
Published: July 2020

Abstract
We focus on a Hamiltonian system with a continuous symmetry, and dynamics that takes place on a presymplectic manifold. We explain how the symmetry can become spontaneously broken by a time crystal, that we define as the minimum of the available mechanical free energy that is simultaneously a time dependent solution of Hamilton’s equation. The mathematical description of such a timecrystalline spontaneous symmetry breaking builds on concepts of equivariant Morse theory in the space of Hamiltonian flows. As an example we analyze a general family of timecrystalline Hamiltonians that is designed to model polygonal, piecewise linear closed strings. The vertices correspond to the locations of pointlike interaction centers; the string is akin a chain of atoms, that are joined together by covalent bonds, modeled by the links of the string. We argue that the timecrystalline character of the string can be affected by its topology. For this we show that a knotty string is usually more timecrystalline than a string with no self-entanglement. We also reveal a relation between phase space topology and the occurrence of timecrystalline dynamics. For this we show that in the case of three point particles, the presence of a time crystal can relate to a Dirac monopole that resides in the phase space. Our results propose that physical examples of Hamiltonian time crystals can be realized in terms of closed, knotted molecular rings.
Synthesis of Al-doped zinc oxide nano particle TCO material by simple Sol-Gel method
Authors: Roy Dhananjoy , Basu M , Paul S 
Published: July 2020

Abstract
Transparent Conducting Oxides (TCOs) are thin films of optically transparent and electrically conductive material. They are an important component in a number of electronic devices including liquid-crystal displays, OLEDs, touchscreens and photovoltaics etc. Indium tin oxide (ITO) is the most widely used TCO but its toxic effect and scarcity in nature causes for high cost of the product and hence technology needs a suitable replacement of it. Out of few replaceable materials, Aluminum doped Zinc Oxide (AZO) semiconductive material has been proven its potential replaceability due to its good transparency in the visible light as well as good conductivity. Also Zinc Oxide is abundant in nature and has no toxic effect. Pure ZnO and AZO sample were synthesized by simple low cost sol gel method and characterized optically and electrically. Effects of Al doping into ZnO nano crystal has been studied on transparency and conductivity aspects. It is observed that in both cases there is an optimum Al atoms concentration governed by the defects introduced by interstitial Al atoms in AZO nano crystal.
Design of a Circular-Slot Multiband (UWB) Antenna with Non-Periodic DGS for WLAN/WiMAX Applications
Authors: Thakur Sunil , Singh Navdeep 
Published: July 2020

Abstract
The paper discusses bandwidth enhancement of a microstrip patch antenna. It explores the application of DGS with parasitic elements to obtain a compact UWB multiband antenna. The antenna is designed on a 14*25 mm2 RT-Duroid (5880) substrate. A comparison is made between four antenna designs with the same dielectric substrate. The antenna design with circular slot on the patch, facilitated with the shorting pins, shows bandwidth enhancement. It uses non-periodic Defective Ground Structure (DGS) for improvement in return loss characteristics, bandwidth enhancement and multiband operation. The slot on the patch provides compact size and DGS gives wide bandwidth (80.5%) with five resonant frequencies of 0.92 GHz, 2.36 GHz, 3.46 GHz, 4.98 GHz & 7.9 GHz making it applicable for GSM (890-966 MHz), WLAN/WiMAX (2.4/3.6/4.9), multi-band applications.
Atomistic simulations of precipitation hardening mechanisms in Mg-Al alloys
Authors: Moitra Amitava 
Published: July 2020

Abstract
Precipitation hardening of Mg-Al alloys primarily comes from the interaction of basal dislocations with Mg17Al12 precipitates. Strengthening of Mg-alloys by precipitation is much less efficient than in other metallic alloys (e.g. Al) and this behaviour has been attributed to geometrical efects, as the Mg17Al12 precipitates grow as thin plates/lozenses or long rod shape parallel to the basal plane. In the present study I focus on the dislocation/precipitate interaction in the athermal limit for both edge and screw type basal dislocations, carried out using molecular statics methodology. In particular, the critical resolved shear stress (CRSS) necessary to overcome the precipitates are determined as a function of the precipitate size and compared with predictions of classical continuum models. These results provide valuable information about the precipitate hardening mechanisms and suggested new avenues to improve the mechanical properties of Mg-Al alloys.
Atom localization in cascade type system
Authors: Mal Kalan , Mondal Suman , Bhattacharyya Dipankar , Bandyopadhyay Amitava 
Published: July 2020

Abstract
A three-level cascade type system is subjected to a standing wave (SW) field acting between the ground energy level and the intermediate energy level of the system and the probe field scans the uppermost energy level from the intermediate energy level. Optical Bloch equations (OBE) for this three-level system are derived from the Liouville equation (Master equation) where the decay terms are added phenomenologically. These OBEs are solved analytically under steady state condition by using weak probe approximation. Under doppler free condition precession of localization was controlled by tuning the SW rabi frequency and relative orientation of the applied fields.
A driven ferromagnetic chain with binary hopping as an efficient spin polarizer
Authors: Sarkar Manik , Dey Moumita , Maiti Santanu K. 
Published: July 2020

Abstract
Spectral properties of a magnetic chain and spin dependent electron transport through it are critically examined in presence of light irradiation. Two different kinds of bonds, long and short are taken into account where each site of the chain is composed of a finite magnetic moment which yields spin dependent scattering to generate polarized currents from a unpolarized one. The degree of spin polarization and its phase can selectively be adjusted with the help of irradiation parameters. All the results are valid for a wide range of physical parameters which suggest that the present proposal can be verified through a suitable laboratory experiment.
Simple, Efficient and Economically Viable Techniques for temperature dependant Thermopower data acquisition of Thermoelectric materials
Authors: Mahakal S , Das Diptasikha , Jana A , Banerjee Aritra , Malik K 
Published: July 2020

Abstract
A simple, economically viable and precise thermopower measurement techniques have been presented in this paper. Continuous data acquisition and simultaneous control of the instruments are achieved by using LabVIEW software. Set-up is built to measure thermopower of the low temperature thermoelectric material down to 10K. A LabVIEW program is developed to collect thermopower data of few μV/K to few hundred μV/K. Thermal stabilization and simple calculations are incorporated to avoid the spurious thermopower. Thermopower measurements, carried out in this set-up are published in reputed journals.
Rapid two-anchor crawling from a milliscale prismatic-push–pull (3P) robot
Authors: Zhou Wei , Gravish Nick 
Published: July 2020

Abstract
Many crawling organisms such as caterpillars and worms use a method of movement in which two or more anchor points alternately push and pull the body forward at a constant frequency. In this paper we present a milliscale push–pull robot which is capable of operating across a wide range of actuation frequencies thus enabling us to expand our understanding of two-anchor locomotion beyond the low-speed regime. We designed and fabricated a milliscale robot which uses anisotropic friction at two oscillating contact points to propel itself forward in a push–pull fashion. In experiments we varied the oscillation frequency, f, over a wide range (10–250 Hz) and observe a non-linear relationship between robot speed over this full frequency range. At low frequency (f < 100 Hz) forward speed increased linearly with frequency. However, at an intermediate push–pull frequency (f > 100 Hz) speed was relatively constant with increasing frequency. Lastly, at higher frequency (f > 170 Hz) the linear speed–frequency relationship returned. The speed–frequency relationship at low actuation frequencies is consistent with previously described two-anchor models and experiments in biology and robotics, however the higher frequency behavior is inconsistent with two-anchor frictional behavior. To understand the locomotion behavior of our system we first develop a deterministic two-anchor model in which contact forces are determined exactly from static or dynamic friction. Our experiments deviate from the model predictions, and through 3D kinematics measurements we confirm that ground contact is intermittent in robot locomotion at higher frequencies. By including probabilistic foot slipping behavior in the two-anchor friction model we are able to describe the three-regimes of robot locomotion.
Teleconnection patterns of precipitation in the Three-River Headwaters region, China
Authors: Dong Yiyang , Zhai Jiaqi , Zhao Yong , Li Haihong , Wang Qingming , Jiang Shan , Chang Huanyu , Ding Zhiyong 
Published: July 2020

Abstract
With the intensification of global warming, spatiotemporal variations in the climate and their mechanisms have received increasing attention. Currently, the relationship between regional precipitation regime, large-scale circulation, and topography, particularly in high-altitude areas such as the Qinghai–Tibet Plateau, are not well understood. Herein, the spatial and temporal variability in the annual and intra-annual (wet and dry periods) precipitation at 33 stations in the Three-River Headwaters (TRH) region from 1967 to 2016 are analysed. Moreover, the empirical orthogonal function and wavelet transform coherence methods are used to analyse the relationships between the different modes of precipitation change and 14 atmospheric circulation indices. The following results were obtained. (1) The mean annual precipitation and mean dry period precipitation significantly increased over the studied period. Annual and intra-annual precipitation showed a spatial southeast-to-northwest decreasing trend. (2) Two main patterns of precipitation were observed during the studied period: a dominant pattern with high- and low-value centres located in southeast and northwest TRH, respectively, and a dipole pattern with more precipitation over southwest TRH and less precipitation over northeast TRH. (3) Precipitation had a negative correlation with latitude, positive correlation with longitude, and nonlinear relationship with elevation. (4) Precipitation changes over various parts of the studied domain were determined based on changes in the weather systems affecting the area, with different indices being correlated with different components during different times of the year.
Topological data analysis reveals parameters with prognostic skill for extreme wildfire size
Authors: Bendick Rebecca , Hoylman Zachary H 
Published: July 2020

Abstract
A topological data analysis (TDA) of 200 000 U.S. wildfires larger than 5 acres indicates that events with the largest final burned areas are associated with systematically low fuel moistures, low precipitation, and high vapor pressure deficits in the 30 days prior to the fire start. These parameters are widely used in empirical fire forecasting tools, thus confirming that an unguided, machine learning (ML) analysis can reproduce known relationships. The simple, short time scale parameters identified can therefore provide quantifiable forecast skill for wildfires with extreme sizes. In contrast, longer aggregates of weather observations for the year prior to fire start, including specific humidity, normalized precipitation indices, average temperature, average precipitation, and vegetation indices are not strongly coupled to extreme fire size, thus afford limited or no enhanced forecast skill. The TDA demonstrates that fuel moistures and short-term weather parameters should optimize the training of ML algorithms for fire forecasting, whilst longer-term climate and ecological measures could be downweighted or omitted. The most useful short-term meteorological and fuels metrics are widely available with low latency for the conterminous U.S, and are not computationally intensive to calculate, suggesting that ML tools using these data streams may suffice to improve situational awareness for wildfire hazards in the U.S.
Political leadership on climate change: the role of health in Obama-era U.S. climate policies
Authors: Workman Annabelle , Blashki Grant , Bowen Kathryn J , Karoly David J , Wiseman John 
Published: July 2020

Abstract
Urgent and ambitious climate action is required to avoid catastrophic climate change and consequent health impacts. Political will is a critical component of the ambitious climate action equation. The current level of political will observed for many national governments is considered inadequate, with numerous political leaders yet to commit to climate action commensurate with the projected risks and responsibilities for their respective jurisdictions. Under the leadership of the Obama administration, however, the United States of America arguably provided an example to the contrary. Strategically utilising an available legislative lever, the Obama administration pursued comparatively ambitious climate change mitigation policies, with health as a core motivation. Analysis of Obama-led climate policies and policy-making strategies provides valuable insight into the utility of health as a motivator for climate action. It also reaffirms that strong political leadership constitutes an essential element in the pursuit of increasingly ambitious climate change policies, particularly in the face of strong opposition.
Local-Wisdom and Its Influence to Disaster Mitigation on the Spatial Configuration of Lakkang Waterfront Settlement
Authors: Syarif E , Asniawaty  , Nadjmi N , Syadzwina A 
Published: July 2020

Abstract
This paper discussed the concept of dwelling and its influence to the disaster-responsive mitigation on the spatial configuration of Lakkang waterfront settlement, as settlement is formed by the local cultural. This research was conducted by using space syntax analysis techniques and supported by the disaster mitigation concept. The result of this study shows that dwelling concepts of Lakkang communities is developed from natural dwelling to collective dwelling. The spatial configuration of Lakkang settlement is developed by collective dwelling. Collective dwelling will form a more integrated space of the space which is formed by natural dwelling. Dwelling culture of the Lakkang people has formed an open space configuration so that the spaces are integrated with each other. The Lakkang settlement is adapted to the natural environment so that disaster can be minimized. The spatial configuration of Lakkang settlement is in accordance with the disaster mitigation concept. The layout of settlements and ecological carrying capacity are the determining factors for disaster response settlements. This paper could be a concept for the development of the waterfront settlements based on local wisdom.
Post-Occupancy Evaluation on Infrastructure Service Performance of Mariso Low Cost Apartment (Rusunawa), Makassar
Authors: Amri N , Idawarni  , Syarif E , Amin S , Siradjuddin Y , Hiromi R 
Published: July 2020

Abstract
This study aims to measure the level of infrastructure service performance of Mariso low-cost apartment (Rusunawa), which is the key to the comfort of occupancy that ensure the sustainability of daily activities both physical and non-physical. Targets to achieve in this research are to formulate the infrastructure service performance according to the standard service of building infrastructure and facilities and as mandated in the standard of planning, building and evaluation of building post-occupancy. This method is used to determine the extent to which the perception of occupants responding to the results of a built environment after more than 10 (ten) years occupied. The applied research method was descriptive research method through the recording and infrastructure service performance analysis by linking between the comfort factor with the standard planning of Mariso low-cost apartment (Rusunawa). The results of the research are the recommendations on the suitability of the service standards/performance infrastructure of the building with the existing conditions of the building with attention to the variable availability of infrastructure that become the focus of research.
Factors Affecting Thermal Comfort of Elementary Schools’ Students in Makassar
Authors: Hamzah B , Mulyadi R , Ishak M T 
Published: July 2020

Abstract
The article aims to analyze the most affecting thermal environmental factors on students’ thermal comfort in elementary schools. The questionnaire has been collected from 1,111 students. The one-minute interval of data measurements was carried out in the 33 classrooms at six primary schools in Makassar. Environmental data involved measurements of air temperature, globe temperature, air velocity, and relative humidity. Students wrote down their personal data and their response to the thermal environments of classrooms in the questionnaire sheets. The results show that the most affecting factor of thermal comfort of students is operative temperature (To). Based on the students’ thermal sensation votes, the operative temperature ranges from 29.1 to 30.0 °C is recommended to provide a comfortable condition for students to learn more successfully in the naturally ventilated primary schools’ classrooms. This result is slightly lower than the neutral temperature obtained from the regression between actual votes and the operative temperature, which was 30.2 °C. The results agree with the neutral temperature calculated using the revised Humphreys adaptive model which give the result of 29.4 °C. The second variable that has a significant effect on the students’ thermal comfort is air velocity. The students felt comfortable at air velocity at about 0.25 m/s and also at air velocity more in the ranges of 1.00 to around 1.50 m/s.
Value of Concrete Compressive Strength on 28 days with Variation of Candlenut Shell Applicated to Plate on a Non-destructive Test Using Hammer Test
Authors: Nasruddin  , Sampebulu V , Mushar P 
Published: July 2020

Abstract
Concrete compressive strength is one of the parameters used to control the quality of a concrete. Concrete compressive strength testing method which is considered the highest level of reliability is a destructive test using a compressive testing machine. Testing requires quite high costs and a longer processing time. But sometimes testing must be done in the scene. Based on the case, a testing tool is needed to measure or determine the compressive strength of concrete without spoil, which is known as the non-destructive test. The tool commonly used for this test is the hammer test. The type of research is experimental. The purpose of this research is to get the compressive strength value of a concrete plate variation of 30% candlenut shells from the test results using a hammer test so as the results can be close to the results of testing using a compressive testing machine (destructive test). The research variable is the testing method (3 point of testing with angle 0°), the age of concrete plate curing, the method of curing (wet curing and dry curing). The number of samples of reinforced concrete slabs is 8 pieces measuring 50cm x 25 cm x 12cm. The research results are Compressive strength of concrete slabs of 30% candlenut shell variations using a Hammer test showed that the concrete strength reached 23-27 Mpa both in wet curing and dry curing or equivalent to the quality of K250 concrete at 28 days. The results also indicate higher values compared to normal concrete slabs.
Identification of Child-Friendly Integrated Public Spaces in Makassar City (Case Study: Losari Beach)
Authors: Ali M , Aliah S E , Fachrul R M , Musdalifah  
Published: July 2020

Abstract
The availability of urban public space supports the survival of the community. The importance of public space sometimes ruled out by the government. The problem that often occurs in urban areas is the transfer of the function of free land to built land. Child Friendly Integrated Public Space (CFIPS) is an open space as a play ground, for the growth and development of children. However, the number and quality of its benefits are still not proportional. In this study taking up waterfront public space in the city of Makassar, case study in the Losari Beach to satisfy the Child Friendly Integrated Public Space aspects, must adjust to the criteria set out in the CFIPS policy. This research was conducted to identify the availability of CFIPS in Makassar City, determine the condition of existing CFIPS and measure the level of visitor satisfaction through direct observation, questionnaires and visitor interviews. The result of this research is the Losari Beach as a friendly public space for children with activities with variable accessibility, safety, comfort, cleanliness and completeness of various facilities of the community views both for the child-friendly aspects.
Soil-Compost Mixture as Alternative Material for Soil Cover Landfill
Authors: Sari K , Ridwan I , Putry M N A 
Published: July 2020

Abstract
One of typical problem in a developing country is the lack of controlling odors, vectors, fires, and litter in the waste landfill. It is known that this problem can be reduced by landfill. However to maintain cover material always available, it is uneasy, especially due to limited budget. This study intends to propose compost-soil mixture as an alternative material using residual soil cover from completed waste landfill. In order to investigate and assess the geotechnical properties of soil-compost mixture as an alternative material, several tests were conducted such as compaction, unconfined compression, and permeability tests. Compaction tests showed 0.4%, 0.8% and 1.2% of compost in soil mixtures results the values of dry density in the range between 1.297 g/cm3 and 1.330 g/cm3, which meet the minimum requirement according to Indiana environmental department USA. Shear strength of compost-soil mixture that derived from results of unconfined compression tests, reduced slightly for additional compost without curing time. However, the values increased sharply for 3 and 7 days of curing time. All the shear strength values of 0.88 kg/cm3 to 34.76 kg/cm3 passed the minimum requirement for cover material according to Environmental Protection Agency (EPA) and Environment Agency. In case of ability of the soil mixture to transmit water, permeability coefficient were 1.5 × 10−3 cm/sec, 7 × 10−4 cm/sec and 3 × 10−4 cm/sec for 0.4%, 0.8% and 1.2% of compost respectively. Referring to modern sanitary landfill and design, it was shown that, the soil mixtures meet minimum requirement for permeability coefficient. To sum up, compost-soil mixtures with composition tested can be considered as material alternative for soil cover in landfill.