bluuebunny/crossref_metadata_2025 huggingface dataset:
The Dantzig selector: recovery of signal via ℓ
1 − αℓ
2 minimization
Authors: Ge Huanmin , Li Peng
Published: December 2021

In the paper, we proposed the Dantzig selector based on the ℓ
1 − αℓ
2 (0 < α ⩽ 1) minimization for the signal recovery. In the Dantzig selector, the constraint ‖
A

⊤
(
b
−
Ax
)‖∞ ⩽ η for some small constant η > 0 means the columns of
A
has very weakly correlated with the error vector
e
=
Ax
−
b
. First, recovery guarantees based on the restricted isometry property are established for signals. Next, we propose the effective algorithm to solve the proposed Dantzig selector. Last, we illustrate the proposed model and algorithm by extensive numerical experiments for the recovery of signals in the cases of Gaussian, impulsive and uniform noises. And the performance of the proposed Dantzig selector is better than that of the existing methods.
Multifractal analysis in non-uniformly hyperbolic interval maps
Authors: Ma Guanzhong , Shen Wenqiang , Yao Xiao
Published: December 2021

In this paper, we establish a framework for the construction of Moran set driven by dynamics. Under this framework, we study the Hausdorff dimension of the generalized intrinsic level set with respect to the given ergodic measure in a class of non-uniformly hyperbolic interval maps with finitely many branches.
Maximisers for Strichartz inequalities on the torus
Authors: Adekoya Oreoluwa , Albert John P
Published: December 2021

We study the existence of maximisers for a one-parameter family of Strichartz inequalities on the torus. In general, maximising sequences can fail to be precompact in

L

2

(

T

)

, and maximisers can fail to exist. We provide a sufficient condition for precompactness of maximising sequences (after translation in Fourier space), and verify the existence of maximisers for a range of values of the parameter. Maximisers for the Strichartz inequalities correspond to stable, periodic (in space and time) solutions of a model equation for optical pulses in a dispersion-managed fiber.
KdV on an incoming tide
Authors: Laurens Thierry
Published: December 2021

Given smooth step-like initial data V(0, x) on the real line, we show that the Korteweg–de Vries equation is globally well-posed for initial data

u

(

0
,
x

)

∈
V

(

0
,
x

)

+

H

−
1

(

R

)

. The proof uses our general well-posedness result (2021 arXiv:2104.11346). As a prerequisite, we show that KdV is globally well-posed for

H

3

(

R

)

perturbations of step-like initial data. In the case V ≡ 0, we obtain a new proof of the Bona–Smith theorem (Bona and Smith 1975 Trans. R. Soc. A
278 555–601) using the low-regularity methods that established the sharp well-posedness of KdV in H
−1 (Killip and Vişan 2019 Ann. Math.
190 249–305).
Singular solutions of the BBM equation: analytical and numerical study
Authors: Gavrilyuk Sergey , Shyue Keh-Ming
Published: December 2021

We show that the Benjamin–Bona–Mahony (BBM) equation admits stable travelling wave solutions representing a sharp transition from a constant state to a periodic wave train. The constant state is determined by the parameters of the periodic wave train: the wave length, amplitude and phase velocity, and satisfies both the generalized Rankine–Hugoniot conditions for the exact BBM equation and for its wave averaged counterpart. Such stable shock-like travelling structures exist if the phase velocity of the periodic wave train is not less than the solution wave averaged. To validate the accuracy of the numerical method, we derive the (singular) solitary limit of the Whitham system for the BBM equation and compare the corresponding numerical and analytical solutions. We find good agreement between analytical results and numerical solutions.
Generic properties of free boundary problems in plasma physics*
Authors: Bartolucci Daniele , Hu Yeyao , Jevnikar Aleks , Yang Wen
Published: December 2021

We are concerned with the global bifurcation analysis of positive solutions to free boundary problems arising in plasma physics. We show that in general, in the sense of domain variations, the following alternative holds: either the shape of the branch of solutions resembles the monotone one of the model case of the two-dimensional disk, or it is a continuous simple curve without bifurcation points which ends up at a point where the boundary density vanishes. On the other hand, we deduce a general criterion ensuring the existence of a free boundary in the interior of the domain. Application to a classic nonlinear eigenvalue problem is also discussed.
Harnessing the potential of recently retired physics teachers to mentor new physics teachers
Authors: Cottle Daniel
Published: December 2021

Three new physics teachers graduating from a university provider of initial teacher education in England were paired with a recently retired physics subject specialist teacher in order to provide informal mentoring during their first year of teaching. The aim of this was to explore if a mentoring intervention of this kind could support teacher knowledge growth of the new physics teachers and influence their retention in the teaching profession. Qualitative data from the study suggests that substantive content of the mentoring discussions that took place addressed issues of general pedagogy and pedagogical content knowledge. The retired teacher mentors were enthusiastic and able to act as mentors. Suggestions emerge for ways of facilitating the mentoring.
Aerodynamic improvement of Darrieus wind turbine
Authors: Goman Oleg , Dreus Andrii , Rozhkevych Anton , Heti Krystyna
Published: December 2021

Until recently, vertical-axis wind turbines are less extensively developed in wind energetics. At the same time, there are a number of advantages in turbines of such type like their independence from the change of wind direction, lower levels of aerodynamic and infrasound noises, higher structural reliability (compared to horizontal engines), etc. With these advantages, vertical-axis wind turbines demonstrate promising capacities. Inter alia, the productiveness of such turbines can be refined through the aerodynamic improvement of the structure and comprehensive optimization of the rotor geometry. The main purpose of the presented paper is to aerodynamically improve vertical wind turbine in order to increase the efficiency of wind energy conversion into electricity. Within the framework of the classical theory of impulses, this article presents a study of the effect of variation in Reynolds number on the general energy characteristics of a vertical-axis wind turbine with two blades. The integral approach makes it possible to use a single-disk impulse model to determine the main specific indicators of the system. The power factor was calculated based on the obtained value of the shaft torque factor, which in turn was determined by numerically integrating the total torque generated by the wind turbine. To calculate the test problem, we used the classic NACA airfoils: 0012, 0015, 0018 and 0021. The proposed calculation algorithm makes it possible not to indicate the Reynolds number and corresponding aerodynamic coefficients at the beginning of the calculation, but to recalculate it depending on the relative speed, position of the airfoil and the linear speed of the airfoil around the circumference. Proposed modern design techniques can be helpful for optimization of vertical wind turbines.
Design, modelling and optimisation of a small-scale Solar Organic Rankine Cycle system for rural power generation
Authors: Patiño L F , Azimov U , Tavera-Ruiz C P , Castellanos J M , Gauthier-Maradei P , Castro L
Published: December 2021

This research study develops the design and model of a Solar Organic Rankine Cycle (SORC) coupled to a bio-digester for small-scale generation in rural areas, in Betulia, Colombia. Moreover, the model is optimised employing a Genetic Algorithm with the software Matlab and the thermodynamic library CoolProp. The objective variables were the mass flow rate of the working fluid, the pressure and temperature of the expander inlet, the solar collectors’ type and the temperature of the water circuit for the bio-digester. The results indicate an overall efficiency between 8.42 and 9.45% with a Levelized Cost of Energy (LCE) between 3.85 and 5.63 £/W. Additionally, the power output is directly related to the mass flow rate of the working fluid. Likewise, increasing the scale of the SORC decreases the LCE. Finally, the results suggest that a superheated fluid reduces the efficiency and the LCE and can deliver more heat to the bio-digester. It is advisable the utilisation of a scroll expander and a counter-flow plate exchanger with a Direct Vapour Generation configuration. The model is a flexible tool capable of integrating more equations and components, with the evaluation of different fitness functions.
Use of renewable energies as part of the strategy to increase the access of energy to remote communities. A Colombian case: Isla Múcura
Authors: Gil Luis Miguel León , Gil Francisco Javier Amórtegui , Reyes Cristian David Rodríguez
Published: December 2021

Use of renewable energies in remote places with no access to main electrical infrastructure becomes fundamental to guarantee equity as well as affordable and clean energy, impacting the United Nations Sustainable Development Goals (UN SDGs). There is also fundamental correct and effective capacitation to operators, to avoid expected-lifetime reductions due to malfunctioning or maloperation. In this paper, the case of Isla Múcura is studied: Photovoltaic (PV) system and storage diagnosis, recovery and community capacitation activities were performed in a fishing and tourism-based community with no knowledge about electrical infrastructure. It was detected that correct capacitation and reliable information devices are fundamental to improve maintenance, operation, and management of the overall generation system
Influence of the volume of ascorbic acid in the synthesis of copper nanoparticles mediated by chemical pathway and its stability over time
Authors: Asmat-Campos D. , Delfin-Narciso D. , Juárez-Cortijo L. , Nazario-Naveda R.
Published: December 2021

In the present investigation, the effect of ascorbic acid volume in the synthesis of copper nanoparticles (Cu NPs) mediated by chemical route and their stability over time was evaluated. For the synthesis, copper sulfate pentahydrate CuSO4 (5H2O) was used as a precursor agent and ascorbic acid (AA) as a reducing agent. Cu NPs was characterized by the following techniques: UV-Visible spectrophotometry to evaluate structural changes that are evidenced in the absorbance peak and atomic absorption spectrophotometry to define nanoparticulate concentrations material in the precipitated and supernatant phases generated. On the methodology it was possible to observe a controlled formation based on the increase in the volume of ascorbic acid in the presence of sodium hydroxide, noticing a production of Cu nanostructures with a tendency to oxidation over time. The UV-visible results showed characteristic surface plasmon resonance peaks of metallic copper for the colloid containing 1.2 mL of A.A; as well as a specific copper concentration of 0.14 ppm in the supernatant and 1519.1 ppm in the precipitate. It is also evidenced that the solution exhibits a rapid reaction on exposure to air by shifting the absorbance peak to 386 nm. In addition, it does not present notable photosensitivity with respect to exposure to sunlight.
Optimal load dispatch strategies for a hybrid system using renewable energy sources
Authors: Ramírez Ronald Ayala , Chacaguasay Javier Tenesaca , García Juan Lata
Published: December 2021

Recently, the idea of hybrid power systems (HES) has attracted interest for the electrification of isolated or energy efficient areas. This document examines the modelling and optimal dimensions of a hybrid microgrid using different dispatch strategies. The sizing of the HES components such as Photovoltaic panels, Batteries, Inverter, a Diesel generator has been optimized by three strategies: (i) load tracking, (ii) cycle load, and (iii) combined dispatch. The location of the case study is in a rural community in Ecuador whose load profile is 17 kW. By utilizing HOMER software, optimization for the HES was achieved with the Combined Dispatch strategy (CD) which presented the minimum levels in the net annual cost (NPC), initial capital, levelized cost of energy (LCOE) of $ 90,073.10, $ 21,208 and $ 0.2016 / kWh, respectively. The conclusions offer a guide to consider the resources and generation combination essential for the optimal operation of an island microgrid with different dispatch scenarios.
Optimal Planning Method of Integrated Energy System Considering Carbon Cost from the Perspective of the Whole Life Cycle
Authors: Bian Bin , Du Zhihuan , Zhou Kui , Huang Tao , Lv Fengbo
Published: December 2021

China commits its goal of peak carbon dioxide emissions before 2030 and achieving carbon neutrality before 2060. The integrated energy system (IES) is one of the critical approaches to achieving the commitments. While the prevailing evaluation method for calculating the carbon emissions of IES neglected parts of factors influence, the result could not reflect the carbon emissions comprehensively. Considering the insufficiency above, in this paper, the evaluation method of carbon emission based on the whole life cycle of IES is proposed. First, based on the IES energy hub model, a typical park’s carbon emission model has been established. Then, the carbon emission coefficients of energy and equipment in production, transportation and operation are analysed, respectively. Hence, a low-carbon operation optimisation model of the IES is proposed. Later, with the lowest annual carbon emission of the integrated energy system as the optimisation target, the IES’s optimal carbon emission allocation and operation plan are proposed, based on the balance between energy supply and demand in the process of energy and equipment use and operation. As a result, the carbon emission of the IES of the park reduces effectively.
Variation of kelulut (Heterotrigona itama) habitat landscapes in South Kalimantan
Authors: Wahyuningtyas R S , Halwany W , Siswadi S , Hakim S S , Rahmanto B , Lestari F , Basiang H A , Alamsyah M S , Susianto A , Buwono D C , Suryanto E , Effendy M , Prianto E , Fahrudin  , Al Aqili I K , Warhamni  , Yusuf M , Suriani
Published: December 2021

Honey production depends on the availability of the landscape as a habitat for producing bee’s food sources. The purpose of this study was to determine different landscapes as a habitat for kelulut (Heterotrigona itama) bees in producing honey from 5 different stingless bee locations. The research was conducted in three districts: Hulu Sungai Tengah, Hulu Sungai Selatan and Tapin District, South Kalimantan Province. This research was conducted to record the types of vegetation in each landscape, which can be divided into three categories; 1 location was a combination type of forest and garden (type 1), 2 locations was a combination type of settlement, shrub, and paddy fields (type 2), and 1 location was a combination type of settlement, plantation, and shrub (type 3). Each meliponiculture also recorded the honey production every month. The results showed that the farmers’ number of beehives was between 96 and 252 hives/farmer. The average production in the rainy season is 0.17 L hive-1year−1, and the dry season is 0.24 L hive−1year−1. Honey production per year for each location was as follows: location type 1 produces 1.59 L hive−1, location type 2 produces 1.85 L hive−1, and location type 3 produces 2.41 L hive−1. Plant identification results at each type of location showed that the number of species found at vegetation cover type 1, 2, and 3 was 116, 128, and 107 species, respectively. At the farms with vegetation cover types 2 and 3, many different flowering shrubs provide year-round forage for the stingless bee.
Identification and classification of cloud computing-based vegetation index values on several lands used in Bogor Regency, Indonesia
Authors: Aprilianti H S , Ari R A , Ranti A , Aslam M F
Published: December 2021

Understanding the threshold value classification from various vegetation types may help distinguish spectral reflectance differences in detailed land use studies. However, conducting all of the processes requires relatively large resources regarding manual computation, which could be surpassed by cloud computing. Unfortunately, in Bogor Regency, there is still a lack of research that studies the threshold value of various vegetation types related to forestry and plantation sectors. Land use categories were classified, and threshold values were determined, especially for selected vegetation types including teak, oil palm, rubber, pine, bamboo, and tea based on several vegetation indices in Bogor Regency using the Cloud-Computing platform. The data source was retrieved from 10-meters Sentinel-2 Satellite median imagery of January 2019 - June 2021. Land use maps were generated using Random Forest Algorithm from composite images. Meanwhile, the threshold value of each vegetation type was calculated from the average and standard deviation of NDVI, SAVI, EVI, ARVI, SLAVI, and GNDVI index. The result of the study showed forest and plantation area covers about 158,168.13 ha or 48.92 % of the study area. NDVI was found suitable to identify teak, SLAVI for rubber and pine, EVI for bamboo and tea, and GNDVI for oil palm vegetation.
Diversity of fig trees in a tropical urban residential area of Sentul City, Bogor, West Java
Authors: Mulyani Y A , Kusrini M D , Mardiastuti A
Published: December 2021

Fig (Ficusspp.) trees have been known as keystone species in the tropics and provide food sources for various species. The study aimed to reveal the diversity of fig trees in a tropical urban residential area of Sentul City, Bogor, West Java, as a part of a bigger study on the wildlife-fig relationship. A purposively selected sample (270 ha of housing, boulevard) and allFicuswere censused. Data on species diversity, height, diameter, and fruiting stage were taken. There were 389Ficustrees, belonging to 10 species, namelyF. benjamina, F. binnendykii, F. caulocarpa, F. elastica, F. kurzii, F. lyrata, F. maclellandii, F. macrocarpa, F. septica,andF. variegata, of which two species (F. lyrataandF. maclellandii) were non-native species.Ficuswere planted as a border, roadsides, shading trees, or ornament. Based on the number of individuals, the most common species wasF. benjamina(63.75%), followed byF. kurzii(14.4%) andF. lyrata(9.5%). As theF. benjaminacan grow big, only about half (56.4%) were in full tree condition, while the rest were pruned (15.5%), trimmed (14.7%), or cut off (13.4%). This study showed that the diversity of fig trees in residential areas of Sentul City, Bogor is affected by the area’s management.
Vegetation distribution analysis of green open space in Binjai Timur, North Sumatera Province using normalized difference vegetation index
Authors: Zaitunah A , Samsuri  , Hidayat N
Published: December 2021

As the city grows, more and more vegetated land is converted to non-vegetated land. This also occurred at Binjai, a city in the North Sumatera Province, Indonesia. The aim of this study was to examine the urban vegetation cover and its changes between 2015 and 2019. The research was carried out in Binjai Timur, which is one of Binjai’s sub-districts. The distribution of vegetation density was measured using the Normalized Difference Vegetation Index (NDVI) value classification. The decrease in the dense class to 10.08 percent was the most significant change in vegetation density class between 2015 and 2019. This was followed by an 8.87 percent increase in the high-density class. This indicates that there is an area with vegetation density increased from lower density to high density. The district has green open spaces in the form of a neighborhood park, cemetery, sub-district park, greenbelt along the road and river, and house yards, according to the field check. These green open spaces were located in low and medium-density areas. The findings suggest that planting trees in those locations and arrangement of vegetation within parks could improve its quality and function. For good quality of urban environments, it is optimizing the use of house yards as vegetated land and boosting green open space quality is required.
Spatio-temporal pattern of urban forest vegetation density, Medan Baru city, Indonesia
Authors: Samsuri  , Ginting C A B , Zaitunah A , Susilowati A
Published: December 2021

The growth of urban areas and the population generally requires the guarantee of a healthy and comfortable environment. The expansion of physical developments and urban areas, year after year, can no longer support human existence. In Indonesia, the city should have at least 10% of its surface area committed to private urban forest and 20% for public urban forest. Jakarta is Indonesia’s largest city, and has only 9.98% urban forest coverage. Medan Baru city is facing the same issue, as it continues to grow year after year. The population requires a comfortable environment, which includes safe drinking water and clean, fresh air. As a result, vegetation is an important component of Medan Baru sub-district that offers numerous benefits. It is necessary to conduct research on the analysis of vegetation density in the Medan Baru, using vegetation indices such as Normalized Difference Vegetation Index (NDVI). The research aimed to analyze vegetation density change and mapping the vegetation density of Medan Baru city. The research found the largest area was relatively dense vegetation, about 262.00 hectares (47.87%). The research also found a decrease in urban forest quality, indicated by an increase in the sparse density class of 41.90 hectares and a decrease in the relative-dense vegetation class with 51.65 hectares. This reduction of vegetation density will reduce the urban forest quality by influencing urban forest capability in absorbing carbon dioxide and alleviating the oxygen productivity volume. Areas with lower stand density must be considered in future urban development planning. Moreover, decrease in vegetation density and urban forest area should be a primary consideration in Medan urban forest management.
Identifying urban food trees in campus green spaces
Authors: Rangkuti A B , Susilowati A , Harahap M M , Iswanto A H
Published: December 2021

The environmental impact of food is one of the drivers of cities’ growing interest in the developed food system in urban areas, one of which is campus green space. Green spaces (GS) on campus accompany native trees, landscaping, and water features for nurturing wildlife and people in the surrounding campus. In addition, GS can provide food sources such as fruit, alternative food, seeds, and nuts. This study aims to identify food trees in 120 hectares of the University Sumatera Utara campus area through field inventory methods. Our research showed that 49 species belong to 18 families and 1536 individuals USU campus produce beneficial food for people surrounding campus, either fruit, nuts, and alternative food. Thus, we conclude that the university’s green space can support the urban area’s vision as food providers and ecological services for achieving urban sustainability. Furthermore, gathering and gleaning from green space provides opportunities for inhabitants to maintain urban resources and deeply interact with nature.
Carbon absorption capability of single-leaf and compound-leaf plants in the BNI Urban Forest, Banda Aceh
Authors: Daud M , Bustam BM , Harnelly E , Dharma W
Published: December 2021

The creation of Open Green Spaces is one of the options for mitigating the impact of global warming. In order to maximize the function of urban forests as carbon dioxide absorbers, plant species selection for urban forests must be considered. The goal of this study was to compare the ability of single-leaf and compound-leaved plants growing in urban forests to absorb carbon dioxide. Exploratory survey methods with purposive sampling were used. The single-leaf plant, B. asiatica (520 cm2), had the maximum leaf area, whereas the single-leaf species, M. elengi had the lowest leaf area (47.50 cm2). The plant with the highest water content in leaves was found in single-leaf plants, B. asiatica (ranging from 74.67 percent to 77.32 percent), while plant F.decipiens from the compound-leaf plant had the lowest water content (ranging from 44.34 percent to 46.14 percent). The plant with the highest percentage of carbohydrate mass at 06.00 am was M. elengi (531.63 percent), and the plant with the lowest percentage of carbohydrate mass was P.indicus (211.15 percent). At 11 am, the compound-leaf plant S.mahogani (496.76 percent) had the largest percentage of carbohydrate mass, B.asiatica had the lowest (289.29 percent). B.asiatica had the most carbon dioxide absorption per leaf area per hour (g/leaf/hour), whereas S. mahogany had the lowest. S.mahogani (32.514 Å) had the highest chlorophyll concentration in the 06.00 am sample, while P.indicus had the highest chlorophyll concentration in the 11.00 am sample (42.440 Å).
Fragmented urban areas: Can plants encourage birds in Jambi City urban space?
Authors: Novriyanti N , Ihsan I , Irawan B , Wulan C
Published: December 2021

This study aims to estimate the extent to which vegetation can encourage the presence of birds in the urban city area. Forest area, urban plantation, grove area, and residential area are The Muhammad Sabki Urban Forest location for bird and plant observed in some circular plots (r=25 m) in the morning and afternoon. Bird directly and identified using a field guide and marked plant species immediately identified using the Plantamor website. The data were analyzed using the Shannon-Wiener Index (H’), The Margalef Index (Dmg), and some using Correlative and regression analysis with IBM SPSS Statistics 28. The results obtained 23 species and a total of 534 individual birds from all observed urban space habitats. All Shannon-Wiener Index (H’) values in each studied habitat type showed a moderate diversity level and low species richness (Dmg). There are 22 plant species that have been identified as places of bird activity. Correlation analysis of the number of plant species on bird species and the number of bird species on bird individuals shows a strong relationship. However, regression analysis shows that the partially analyzed variables have no significant effect, so additional values are needed from other factors.
Growth performance of eucalypts and acacia seedling under elevated CO2 load in the changing environment
Authors: Novriyanti E , Watanabe M , Mao Q , Takayoshi K
Published: December 2021

Acacia and Eucalypt are important species in the global forest plantations. The resilience of those species under the changing environment would define their significance in the dynamic of forest plantation. This study was aimed to provide information on the growth performance of two acacias and two eucalypts seedlings under elevated CO2 concentrations. The seedlings of A. auriculiformis, A. mangium, E. camadulensis, and E. urophylla were subjected to two levels of CO2 and two levels of nutrient supply in the FACE system in Sapporo Experimental Forest, Japan. The eucalypts showed significantly higher growth performance than the acacias. The nutrient addition significantly increased the growth, yet the CO2 and interaction between CO2 and nutrients were not significantly different. LMA was not significantly affected by the elevated CO2 and nutrient addition. Although nutrients significantly affected the C/N in the eucalypts, they showed no different effect on the acacias. As expected, Nmass and Narea were higher in the acacia than those in the eucalypts, although no significant responses were shown to elevated CO2 and nutrient addition. The tested acacia and eucalypts showed relatively insensitivity to elevated CO2. Thus they might possess resilience capacity under the keep increasing level of the atmospheric CO2 concentration.
The pattern of germination of teak mistletoe seeds in relation with parasitism
Authors: Muttaqin Z , Sri W B , Basuki W , Siregar I Z , Corryanti
Published: December 2021

The objectives of this research are to test the initial viability and germination pattern of teak mistletoe seeds, namelyDendrophthoe pentandraandMacrosolen tetragonusin associated with parasitism. Research results showed that the pattern ofD. pentandragermination was different from that ofM. tetragonus. The germination process ofD. pentandrashowed incomplete development of germination morphology, marked by an absence of development or growth of hypocotyl and cotyledon. Parasitism was more dominant inD. pentandra, supported by the fact that the sum of mean germination day (RH) in the stem of teak seedling was faster (17.54±2.77 days), as compared with that ofM. tetragonus(35.13±1.76 days), although mortality ofM. tetragonusseedlings was very low (±3%), whereas that ofD. pentandrawas fairly high (±34%). It was related to the life cycle ofM. tetragonus, which was longer than that ofD. pentandra. In the attachment of seeds in the standing tree stems, it was proven that the germination percentage (%K) ofD. pentandra(38.5%) was higher than that ofM. tetragonus(11.1%). Seed germination ofD. pentandrafrom bird feces also showed that %K (46.4%) was higher than seed attachment in tree stem, includingM.tetragonus.It was supposed that there was a correlation between the easiness of germination and parasitism character in teak mistletoes. It was considered that parasitism ofD. pentandrawas more prominent than that ofM. tetragonusin a teak host.
UFMonev application design for managing urban forest data and information
Authors: Christiani N , Hidayat Y , Sutrisno
Published: December 2021

Fallen tree incidents in urban areas are frequently reported and often result in loss of property and even death. Therefore, tree health monitoring in urban forests needs to be carried out regularly. The tree health monitoring and evaluation (monev) requires a large amount of time, money, and labor, while the availability is very limited. This condition leads to the lack of tree health monitoring in the urban forest. Up to now, monev activities and reports are still conducted traditionally by using pen and paper. This method has many shortcomings such as ineffectiveness and inefficiency during monev and less engagement of the results. To solve this problem, the method must be modified in a new approach that is relevant to today’s era of Industry 4.0, namely the Internet of Things. This study aims to overcome the shortcomings by designing a Management Information System (MIS) named UFMonev. UFMonev was developed by prototyping method using kodular. Analysis in the information system was carried out by assessing the physical condition of the tree. UFMonev was built in the form of an application that is operated via a smartphone. This application can only be accessed by the party responsible for managing trees in urban areas.
Eucalyptus forest plantation assessment of vegetation health using satellite remote sensing techniques
Authors: Razali S M , Lion M
Published: December 2021

Early examination of the water condition of the plants utilizing remote sensing technology can be used to assess the health of the vegetation in the Eucalyptus forest plantation. To preserve a sustainable wood supply and wooded region that is necessary to human life and vital wood supplies, the forested region should be protected from disease and environmental damage. Disease and environmental impacts are two of the most critical challenges in Eucalyptus forest management. To calculate the vegetation index and identify land cover in the research region, remote sensing with Catalyst Professional software based on Object Analyst (OBIA) tools was utilized. The NDVI (Normalized Difference Vegetation Index) is a valuable index for assessing early vegetation health. For atmospheric correction and haze removal, the image was first pre-processed with ATCOR tools. Second, the image was converted to NDVI using algorithm library tools. In addition, for land cover classification in the area, an OBIA based on Support Vector Machine (SVM) was utilized, followed by an accuracy assessment. Using ArcGIS software, zonal statistics were used to calculate the NDVI value for each land cover category. According to the method, the map produced roads, plantations, buildings, low-density vegetation, oil palm, and open area classifications. Based on accuracy assessment in OBIA, plantation, oil palm, and open area were all 100% accurate, whereas low-density vegetation and oil palm were 100% accurate according to the user. Producer accuracy was lowest on roads, whereas user accuracy was lowest in open areas. Non-vegetated land is difficult to classify at this site, according to the accuracy assessment results. The map improved accuracy since the study used a lower segmentation scale factor of 50, which produced fine vectors ascribed for classification. The average NDVI for oil palm area was 0.71, and 0.69 for plantation. Because it was difficult to classify open areas and roads, the NDVI for the class was low, at 0.37 and 0.22, respectively. From land use classification, the plantation was classified (37%), low-density vegetation area (28%), and oil palm (21%). Others make up only 2 to 7% of the site’s overall area. According to the study, NDVI is a useful indicator for assessing the health of vegetation in areas where NDVI values are larger than 0.70 and presents pf mixed landscape and non-vegetated features. A higher NDVI value implies that the plant is in good enough shape to conduct photosynthetic activities thus producing biomass for sustaining vegetation health. This type of inquiry can forecast more indices to produce higher accuracy of land use maps for the Eucalyptus plantation. At the same time, this type of research can assist forest managers in detecting large areas in their plantation for vegetation health assessment such as for early disease detection.
Monitoring of Ganoderma spp. on the trees at Arboretum of Universitas Gadjah Mada, Yogyakarta, Indonesia: Implications for health care recommendation of old trees
Authors: Rahayu S , Utomo D S , Cahyanto V E , Anggara G , Adriyanti D T , Nurjanto H H , Kristian A A
Published: December 2021

The arboretum of Universitas Gadjah Mada (UGM), Yogyakarta, established in 1963, is host to various plants and trees originating from across Indonesia. Due to poor management and climate change, several cases of tree death and decline related to the Ganoderma sp. attack have been reported since 2015. The aims of this research were to evaluate the occurrence of root rot disease and to monitor the spatial and temporal distribution of Ganoderma spp. Completely survey on 638 trees with DBH more than 10 cm, monitored the number of basidiocarps attached on each infected species tree, and assessed the leaf and canopy condition were conducted on 2018 to 2021. The result showed that 0.78 % of trees with more than 10 cm diameter were infected by Ganoderma sp. since 2018 and become 1.57% in 2021. The species trees of Pterygota alata (1 tree), Pterocarpus indicus (1 tree), and Adenanthera pavonina (8 trees) were attacked by Ganoderma with a disease severity index of 25% to 100% in September 2021. The spatial pattern of trees associated with Ganoderma was random. However, since the density of trees at the arboretum is dense, the potential Ganoderma spreading through root contact will be high. Regular monitoring for early detection has to be conducted to prevent advanced infection and to set health care recommendations for infected trees with a high scientific value.
An overview of recent advances in sediment microbial fuel cells for wastewater treatment and energy production
Authors: Emalya N , Munawar E , Suhendrayatna S , Fathanah U , Yunardi Y
Published: December 2021

In developing countries, the presence of wastewater is undesirable due to a costly investment for the treatment unit and energy-intensive for the operation. The wastewater treatment units in developing countries usually are not appropriately operated due to lacking operational cost. Therefore, it is not surprising if wastewater has never been considered a potential resource, even though it is rich in organics and nutrient substances. Biological treatment enables the conversion of wastewater into valuable products and energy. Sediment Microbial fuel cells (SMFCs) are emerging technologies envisaged as a feasible solution for simultaneous removal of carbonaceous compounds and generation of electricity. In SMFCs, power can be generated naturally by embedding an anode in the sediment and immersing the cathode in the water above the sediment. One of the most significant obstacles to upscaling and practical applications of the SMFCs appears to be the low-power output. The entire performance of an SMFC is determined by microorganisms, proper electrode materials, optimal SMFC designs, and process parameter optimization. This paper will discuss the recent progress of SMFC research related to its application in wastewater treatments and energy production. The advantages and obstacles of using SMFC in wastewater treatment are also presented.
Feasibility of using low resin content levels in the production of bamboo particle composite: basic properties
Authors: Bahari S A , Abu F , Zakaria M N , Osman S , Appiah-Kubi E
Published: December 2021

In this study, the suitability of Semantan bamboo (Gigantochloa scortechinii) particles in the production of single-layered composite board was investigated. The effects of different resin types and lower resin content levels on the basic properties (mechanical and physical properties) of particle composite board made from G. scortechinii were determined. The 12-mm thickness boards with dimension of 340 × 340 mm and targeted density of 660 kg/m3 were fabricated. Types of resin used were melamine urea formaldehyde (MUF) and urea formaldehyde (UF), while resin content levels were 3.5 and 5%. In general, the mechanical and physical properties of board blended with MUF resin were better than UF due to the presence of melamine in MUF that influenced the properties. Board made from 5% resin content were better in term of mechanical and physical properties than 3.5% resin content levels. 5% resin content level had increased the particles bonding ability, thus influenced the excellent properties of the board. However, in general, the properties of bamboo particle composite board in this study were not comparable to the board made from wood. Only IB properties of bamboo particle composite board exceeded the minimum requirements as stipulated in standards. As a consequence, the information of particle composite board made from bamboo is important in assessing bamboo’s usefulness as an alternative raw material for wood-based industries. The final results obtained could be used as reference for researchers and manufacturers.
Particle size distribution and clay minerals in dryland soils of Aceh Besar, Indonesia
Authors: Sufardi S , Arabia T , Khairullah K , Apriani I
Published: December 2021

Soil particle size distribution is a fundamental physical property affecting other soil properties. This research aims to determine the distribution of soil particles and the composition of clay minerals on each layer of the horizon in four soil profiles (P1, P2, P3, and P4) with different parent materials in the dryland of Aceh Besar district which includes Entisols Jantho, Andisols Saree, Inceptisols Cucum, and Oxisols Lembah Seulawah. Particle size distribution (or texture) and bulk density (BD) were analyzed in the laboratory. Soil structure and consistency were observed directly in the field. The type of clay minerals was identified by X-ray diffraction, while Fe, Al, and Si-oxide were extracted by dithionite-citrate solution. The results shown that the particle size distribution and the physical properties of dryland soils of Aceh Besar vary between soil orders. Andisols Saree has better physical properties than the physical properties of other soils and low bulk density. The Al, Fe, and Si fractions and clay mineral composition in the soil profiles also vary considerably between soil orders. The Andisols are dominated by allophane minerals (amorphous fractions) while Entisols, Inceptisols and Oxisols consist of mixed minerals of feldspar, quartz, halloysite, goethite, and other clay minerals. These soil orders have some soil physical constraints i.e. high soil bulk density, low water holding capacity and poor soil structures. Improvements in the physical properties of the soil on Aceh Besar dryland are indispensable to improve the quality of the soil.
Effect of selection methods on seed potato quality in the following season
Authors: Gunadi N , Pronk A , Kartasih A A , Prabaningrum L , Moekasan T K , Hengsdijk H
Published: December 2021

Most potato farmers in Indonesia select the small tubers at harvest for planting in the following season, the so-called farmers’ practice (FP). This propagation method is cheap, but the small tubers may come from less healthy plants, which increases the build-up of diseases with accelerated yield decreases over the seasons. Alternatively, farmers may identify healthy plants within the growing season and select those for propagation, the so-called positive plant selection method (PPSM). An experiment was carried out to evaluate the effects of PPSM compared to FP on yields in the following season in the two main potato growing areas of West Java, i.e., Pangalengan and Garut. Generations G2 and G3 of cv. Granola and one generation of the imported cv. Atlantic were used. Selected seeds using PPSM and FP were planted in the second season in a randomized complete block design. Results show that yields of seeds selected through PPSM were significantly higher compared to seeds selected through FP, over both locations, on average, 7.4, 5.5 and 1.2 ton ha−1 for Granola G2 and G3, and the Atlantic, respectively. These yield increases represent an increase in the gross revenue of 30.8 to 51.8 million IDR ha−1 for Granola and 1.9 to 7.8 million IDR ha−1 for Atlantic at a farm gate price of 7,000 and 6,500 IDR kg−1, respectively. This study confirms that PPSM is superior to FP and improves the quality of the farms saved seeds.
The effect of CO2emissions in Indonesia
Authors: Yusuf Z , Wardhiah  , Syamni G , Siregar M J A , Sitepu Y A
Published: December 2021

This study was conducted to examine the effect of the variable use of CO2 emission gas and export variables on Indonesia’s economic growth. The data used in this study are time series data from the two variables for the period 2004 to 2019. All data were obtained from the world bank and accessed through the www.data.worldbank.org. The data analysis method used in this study uses an autoregressive distributed lag (ARDL) model approach. The ARDL model is used to examine the short-term and long-term effects of CO2 gas emission variables and export variables. The results of the study found that the variable use of CO2 emission gas in the short term had a positive and insignificant effect on economic growth. The export variable has a significant positive effect on economic growth. Meanwhile, in the long term, the variable use of CO2 emission gas and the export variable has no effect on Indonesia’s economic growth. This finding shows that Indonesia’s economic growth is still determined by exports, but in the long term the government must work harder to increase its exports. In addition, export activities must not lead to the use of excessive CO2 emissions.
The effect of planting season on physical and chemical characteristics of local rice varieties
Authors: Fahmy K , Yanti D , Permata D A
Published: December 2021

The season is the time interval with the most frequent weather. The rainy season is the time when it rains a lot, while the dry season is the time when it rains a little. Planting season is one of the factors that affect the quality of the grain, which directly determines the quality of rice. This study aims to determine the effect of the growing season on the physical-chemical characteristics of rice. The sample observed was the Bujang Marantau rice (local variety) which was taken from two seasons (dry season and rainy season) in the same location, which is Nagari Singkarak, X Koto Singkarak District, Solok Regency, West Sumatra Province. The physical characteristics examined were head rice, broken rice, and groats. Chemical characteristics analyzed were amylose content determined by the IRRI method (1971). Meanwhile, water content and ash content were analyzed by the gravimetric method. In addition, fat content was determined by the Soxhlet method with Weibull modification. Furthermore, protein content was determined by the Kjeldahl method. The results showed that the growing season did not affect the ash content, fat content, and carbohydrates of the Bujang Marantau rice, but affected the water, protein, and amylose content. Based on the quality requirements (SNI 6128:2015), Bujang Marantau rice is included in the medium quality class 1.
Temperature coverage simulation of horizontal cylinder type coffee roasting machine
Authors: Fachruddin F , Syafriandi S , Fadhil R
Published: December 2021

This study aims to simulate the temperature distribution of coffee roasting machines and study the profile of coffee beans roasted using a horizontal cylinder-type roaster. The coffee used in this study is arabica. The simulation method for the temperature estimation in the coffee roasting process uses the Solidworks Flow Simulation 2016 software, while the actual temperature measurement using a thermocouple is simulated with the Surfer software version 16. Furthermore, each stage of the coffee roasting process has been carried out, including the weight of the material, the roasting temperature, and the bulk density. The final step is to observe the profile of the roasted coffee beans at every minute of treatment. The study results indicate a difference between the approximate temperature simulation (top 176.85°C, bottom 191.97°C) and the actual temperature measured results (upper 214°C, bottom 220°C). The weight of the material (coffee green bean), the roasting temperature, and the bulk density during the test experienced regular movements from the beginning to the end of the treatment. The profile of roasted coffee beans shows a darker color movement along with the longer roasting time used. The profile of the roasted coffee beans will be beneficial in determining at which level of roasting you want (light, medium, medium-dark, dark).
Performance test of air input control system for paddy grain drying using in-store dryer
Authors: Nurba D , Agustina R , Yasar M , Khurjannah A
Published: December 2021

The control system is e series of a system that is very important in today’s technology. Wherewith control system can make the human job easy and get a good result. This study used a controlled In-Store Dryer to dry 100 kg of grain with an initial moisture content of 17,77% to reach 14%. The study results using a control system, the average ambient temperature of the three tests ranged from 32°C to 33°C, and the RH ranged from 64,8 % to 68,6%. At the same time, the average temperature was 36,7°C to 37,5°C, and the average RH was 49,9% up to 64,7%. The drying airflow speed at the fan input is 6,2 m/s and at the chimney 9,2 m/s. Moisture content during drying differs for each thickness depending on the location, with an average drying rate of 0,92%. During drying, the moisture content varied for each consistency depending on the site, with the drying rate at an average ISD of 0.92% w / hr. total electrical energy consumption of 32.57 kWh and energy in biomass combustion 1,416,600 kJ. The quality during rice drying starts from the initial moisture content of 17.78% to reach the final moisture content of 10.44%.