bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Study on the Performance of Ship Pipeline Coated Vibration Isolator
Authors: Lao Xingsheng , Liu Yong , Dai Chunhui
Published: January 2021

In order to improve the efficiency of ship pipeline vibration isolation, an optimized design scheme of coated rubber vibration isolator was proposed. The natural frequency was calculated and a test bench was established for vibration isolation performance test. The results show that the dynamic and static stiffness of the optimized vibration isolator is significantly lower than the traditional design value at the natural frequency. The natural frequency of the vibration isolator is reduced from about 35Hz to about 9.7Hz from the initial design scheme, and the vibration isolation efficiency is increased from about 20dB to about 33dB as well.
Conversion from Free-Form Surface to Ruled Surface of Centrifugal Compressor Impellers
Authors: Guo Feng , Chen Hua , Li Xiangjun
Published: January 2021

At present, there are several conversion methods exist, which are based on cutter fixing at a point on the blade surface to swing around the blade surface, searching for a position where the error between the cutter and the free-form surface is the smallest. They rarely take into account the benefit from searching cutter position along the blade’s tangential direction, and ignore the possible optimal cutter position from such search. In this paper, we propose a new cutter search method that allows this tangential swing in additional to meridional plane swing of the cutter in searching for the optimal position of the cutter. The mathematics of the method is described, and two different centrifugal compressor impellers with free-form blade surfaces are employed as test cases. The results show that this method can well convert the free-form surfaces of the impeller blades into ruled surfaces.
Research on Damping Mechanism with Resetting Capability for Axial Vibration Control of Satellite Antenna
Authors: Wang Min , Liu Jiaxing , Liu Qinda , Zhao Tingting , Zhang Yunfei
Published: January 2021

With the development of space technology, the large scale space deployable antennas gradually become one of the key research themes of research. The basic requirements for large scale satellite antennas are the characteristics of light in weight and high in profile accuracy. The low-frequency and large-amplitude vibration of the large scale antennas is easily excited when working in an environment with zero gravity. In order to suppress the vibration of large scale deployable satellite antenna, a new type of damping mechanism with resetting capability is presented to improve the ability of vibration energy consumption and ensure the dynamic characteristics of the radial rib structure containing the presented profile accuracy of the antenna. The rod making up the deployment mechanism of the antennas is divided into two parts which connected by using the shape memory alloy (SMA) wires through guiding mechanism. Meanwhile, a metal rubber is fixed and pressed between two parts of the rod by SMA wires. The ability of the friction energy dissipation of the metal rubber is utilized to suppress the axial vibration of the rods. The super elasticity of the SMA wires is used to provide the restoring force for ensuring the dimensional stability of the rod. In this paper, the design principle of the axial self-resetting damping structure is introduced in detail. And, the dynamic characteristics of the radial rib structure containing the presented damping mechanism are investigated by using the software ANSYS. The simulation results show that the vibration amplitude of the radial rib of antennas has been reduced significantly.
A damage-coupled viscoplastic model for compressed asphalt concrete
Authors: Zeng Guowei , Liu Lei , Bai Fan
Published: January 2021

The damage theory is employed to investigate the mechanical strength deterioration caused by micro defects. Introducing the effective stress, this paper presents a damage-coupled viscoplastic model by applying the Schwartz model with an elastic component. The model is calibrated and validated by asphalt concrete creep test under various stresses. With the help of recursive numerical method, the model parameters include viscoplastic and damage functions for different stresses are determined. The result shows the model not only characterize the three stage creep deformation behaviour at a range of stress, but also can predict the damage evolution during the increased creep strain.
Matching and Analysis of Ethanol Engine and Transmission System of Light Passenger Car
Authors: Sun Shuguang , Wang Meng , Zhang Desheng
Published: January 2021

In the process of the matching of ethanol engine and transmission system with a new light passenger car, it is found that the traditional theory formula is complex, and with long time of debugging process and low accuracy. By using Cruise software, the performance simulation model of passenger car is built, simulation tasks are established. Different matching scheme is set up and the simulation calculation of power performance and fuel economy are carried on. The comprehensive evaluation system of index weight is established by analyzing the simulation results. According to the index weight and the simulation result, a better set of combining scheme for vehicle with comprehensive performance indicators can be obtained.
The vibration reduction optimization of the body tube fastening of EM rail launcher
Authors: Lian Zhongmou , Feng Gang , Li Tengda , Liu Shaowei
Published: January 2021

In order to further optimize the vibration reduction effect of the body tube fastening of the electromagnetic rail launcher, the vibration reduction optimization scheme of the body tube fastening is determined by the modal superposition method. The electromagnetic rail launcher is simplified to Bernoulli-Euler beam, the vibration equation of the rail is established, and the inherent characteristics of the rail are analyzed. The multi-field coupled finite element model of the electromagnetic rail launcher is established and the complete transient launching process of the launcher is simulated. Based on the modal analysis of the system stiffness at the critical velocity, the optimal position of the tube fastening is determined, and the influence of different fastening positions on the damping effect is analyzed. The results show that the fastening of the body tube can effectively improve the structural stiffness of the electromagnetic rail launcher, and the damping effect of the fastening is affected by the vibration characteristics of the fastening position. The addition of fastening leads to the stress concentration in the adjacent part of the rail, which increases the requirement of rail strength. When the fastening is set in the front part of the rail, the vibration reduction effect is obvious. When it is set in the back part, the resonance range of the critical velocity should be avoided and the priority should be given to the position before the critical velocity.
Study on the optimization of on-line drilling parameters of slim cigarette to the stability of total ventilation rate
Authors: Qiao Xiaohui , Zhao Jian , Hu Qun , Zhang Tao , Yang Lei , Wu Jiacan , He Xufeng , Xu Yanqun , Pu Qian , Zhao Meiwei , Qiu Ye , Feng Hongtao
Published: January 2021

In order to explore the influence of the number of holes and laser pulse durations on the mean and standard deviation of the total ventilation rate of the slim cigarettes, the optimal range of on-line drilling parameters for different products under the allowable range of the total ventilation rate was determined. In this study, three cigarette products were used, 40 holes (before improvement), and 30 holes (after improvement) were drilled by on-line laser, and the laser pulse durations were adjusted to make the mean of total ventilation rate reach the standard value for comparative analysis. The results show that when the optimal number of holes is 30, the standard deviation of the total ventilation rate of each brand decreases by 24.79%, which increases the stability of the total ventilation rate.
Simulation analysis of gear contact stress in reduction gearbox
Authors: Yang Feng , Fu ZhongYuan , Tian ZhaoDan
Published: January 2021

In this paper, the contact stress of reducer gears is simulated and analyzed, and the assembly error is considered. Application of three-dimensional modeling software SolidWorks helical gear model is set up, and carried out in accordance with the working condition of two kinds of error assembly, including the backlash error and axis parallelism error, and the finite element analysis software ANSYS, the contact surface and tooth root, the contact stress of the online statics and dynamics analysis, it is concluded that the stress under two kinds of error and change situation, the size of the summary analysis of the influence on gear transmission, in the future has reference and guiding significance to the actual production of gear assembly. Combining the powerful modeling function of CAD software with CAE, it embodies the integration of CAD and CAE technology.
Analysis of Strength Stiffness and Modes for Bus Body Frame
Authors: Yao Chunge , Yang Mengjie
Published: January 2021

In this paper, the bus body frame is made as a research object. The finite element model of bus body frame is built in Hypermesh software. The static strength and stiffness of bus body frame under four typical working conditions are calculated by Nastran solver. Modal analysis is carried out by Lanczos method, low natural frequency and vibration mode are obtained. The analysis of results show that the strength and stiffness of bus body frame must meet design requirement, and the modal frequency is also within the design range. According to finite element analysis, the development cycle of new product is reduced, and theoretical basis for later model improvement and optimal design is provided.
The Sufficient Conditions of The C*-Module C*m to become a C-Subcomodule
Authors: Puspita N P , Wijayanti I E , Surodjo B
Published: January 2021

Let R be a commutative ring with identity and M be a comodule over R-coalgebra C. It was already well-known that any C-comodule M is a module over dual algebra C* where C* is the set of all R-module homomorphisms from C to R. Furthermore, the category of comodule is a subcategory of the category of C*-module. Hence, any C-subcomodule of M is a C*-submodule of M, and the conversely is not true. For any non zero element m in M, C*m is a C*-submodule of M. In general, C*m is not to become a C-subcomodule of M. By using the theory of exact sequences in modules and the theory of categories, we give a condition such that C*m to be a C-subcomodule of M.
Solution Formula of the Compressible Fluid Motion in Three Dimension Euclidean Space using Fourier Transform
Authors: Alif A H , Maryani S , Nurshiami S R
Published: January 2021

We derive a detailed determination of the solution formula for the compressible viscous fluid flow in three dimensional Euclidean space using Fourier transform. For the further research, we can not only generalized the model problem to the N-dimensional Euclidean space (N>3) but also we can estimate the solution operator families of the model problem.
The Locating Chromatic Number for Split Graph of Cycle
Authors: Prawinasti K , Ansori M , Asmiati  , Notiragayu  , G N Rofi AR
Published: January 2021

The minimum number of colors in a locating coloring of G is called the locating chromatic number of graph G, denoted by χL
(G). Split graph of cycle with a set of vertices {υ
1, υ
2, υ
3, …, υ
n} is graph obtained by adding on vertex υi
as many new k vertices

υ

i

1

,

υ

i

2

,

υ

i

3

,

…

,

υ

i

k

, so that each vertices

υ

i

1

,

υ

i

2

,

υ

i

3

,

…

,

υ

i

k

neighbouring with each vertex that is neighbouring to vertex vi
in the cycle graph. Split graph of cycle, denoted by spl(Cn
) In this paper will be discussed about the locating chromatic number for split graph of cycle.
Application of Vector Error Correction Model (VECM) and Impulse Response Function for Daily Stock Prices
Authors: Winarno S. , Usman M. , Warsono  , Kurniasari D. , Widiarti
Published: January 2021

Vector Error Correction Model is a cointegrated VAR model. This idea of Vector Error Correction Model (VECM), which consists of a VAR model of the order p - 1 on the differences of the variables, and an error-correction term derived from the known (estimated) cointegrating relationship. Intuitively, and using the stock market example, a VECM model establishes a short-term relationship between the stock prices, while correcting with the deviation from the long-term comovement of prices. An Impulse Response Function traces the incremental effect of a 1 unit (or one standard deviation) shock in one of the variables on the future values of the other endogenous variables. Impulse Response Functions trace the incremental effect of the marketing action reflected in the shock. The data used in this analysis are 4 (four) daily plantation stocks prices in Indonesia with time period of January to July in three years which are 2018, 2019, and 2020. The objective of this study is to determine the relationship among 4 (four) stocks prices with VECM and to know the behaviour of each stocks prices with Impulse Response.
Quantitative Method For Analysis of Non-Performing Financing Return: A Case Study on Assets of PT. BSM
Authors: Nurvazly D E , Muharramah U , Zakaria L , Chasanah S L , Ferdias P
Published: January 2021

There are several ways to describe data mathematically. Likewise with the computing tool. As a computational aid, Mathematica® is designed to make it easier for users to carry out the calculation process symbolically or numerically. This article will discuss the use of Mathematica® to describe banking data through quantitative methods. A case study that discussed in this article is the results of the analysis of the influence of Non-Performing Financing (NPF) against the financial performance of PT. Bank Syariah Mandiri (BSM) through indicators of Return on Asset (ROA). Research conducted using a quantitative approach to the data of the financial statements of PT BSM. The sampling technique used was purposive sampling criteria the Public Sharia Banks publish annual financial statements in the period 2009-2018 with > 75 trillion rupiahs in assets. Based on quantitative method using Mathematica® programming, the research data has a normal distribution and no deviation from the rules of classical assumptions. In addition, the diversity of the data being used can explain the regression models constructed by the NPF variable towards the ROA variable, and the hypothesis testing results show that the variables of NPF have a significant, negative effect on ROA.
Sub-Exact Sequence On Hilbert Space
Authors: Utami B H S , Fitriani  , Usman M , Warsono  , Daoud J I
Published: January 2021

The notion of the sub-exact sequence is the generalization of exact sequence in algebra especially on a module. A module over a ring R is a generalization of the notion of vector space over a field F. Refers to a special vector space over field F when we have a complete inner product space, it is called a Hilbert space. A space is complete if every Cauchy sequence converges. Now, we introduce the sub-exact sequence on Hilbert space which can later be useful in statistics. This paper aims to investigate the properties of the sub-exact sequence and their relation to direct summand on Hilbert space. As the result, we get two properties of isometric isomorphism sub-exact sequence on Hilbert space.
The Formula to Count The Number of Vertices Labeled Order Six Connected Graphs with Maximum Thirty Edges without Loops
Authors: Puri F C , Wamiliana  , Usman M , Amanto  , Ansori M , Antoni Y
Published: January 2021

If for every pair of vertices in a graph G(V,E) there exist minimum one path joining them, then G is called connected, otherwise the graph is called disconnected. If n vertices and m edges are given then numerous graphs are able to be created. The graphs created might be disconnected or connected, and also maybe simple or not. A simple graph is a graph whose no paralled edges nor loops. A loop is an edges that connects the same vertex while paralled edges are edges that connecting the same pair of vertices. In this research we will discuss the formula to count the number of connected vertex labeled order six graph containing at most thirty edges and may contain fifteen parallel edges without loops.
Modeling Autoregressive Integrated Moving Average (ARIMA) and Forecasting of PT Unilever Indonesia Tbk Share Prices During the COVID-19 Pandemic Period
Authors: Putri R N , Usman M , Warsono  , Widiarti  , Virginia E
Published: January 2021

ARIMA method is one method that can be used in predicting the movement of company shares. This study aims to obtain a time series model with the ARIMA method and predict stock price data of PT Unilever Indonesia Tbk from January 2020 to June 2020. The best model that fits the data based on the MSE value is the ARIMA(1,1,1) model. The ARIMA model (1,1,1) shows a match between real data and the predicted value. This model is then used for forecasting the next 14 days. Data on UNVR stock price from January 2020 to June 2020 are below 8000, this seems to correlate with the current conditions, namely the Covid-19 pandemic. Forecasting for the next 14 days (two weeks) from July 1, 2020 to July 14, 2020, the forecast values have a trend decrease, the trend of PT. Unilever Indonesia Tbk has been going down since January 2020. This seems to have occurred as an implication of the Covid-19 pandemic from January 2020 to the present.
Web GIS based assessment using SAW methods to identify high risk areas of tuberculosis transmission and incidence in Bandar Lampung City
Authors: Hijriani A , Cahyani A
Published: January 2021

Tuberculosis (TB) is still a major problem in the public health sector, even in 2016 Indonesia was included in the five countries with the highest TB case burden in the world. In 2017, the number of TB cases in Lampung Province was 7,040 cases and one of the obstacles faced was the tendency for TB sufferers to be difficult to open so that many cases were not detected. Based on these facts, a Geographical Information System (GIS) is proposed which can process data into maps to see high risk areas where TB disease was found in Bandar Lampung. It will make it easier for health agencies to make policies in handling or preventing TB disease in Bandar Lampung. In this study, a decision-making system with Simple Additive Weighting (SAW) method was also proposed to produce a map of the area with the level of TB risk factors. The criteria used to summarize the weights are TB cases, population density, mortality, healthy and clean behavior, and health facilities. The result of data processing is presented in a color polygon map that has 4 levels of risk factors, namely very high, high, medium, and low.
Implementation of K-Means Algorithm for Clustering Corn Planting Feasibility Area in South Lampung Regency
Authors: Aldino A A , Darwis D , Prastowo A T , Sujana C
Published: January 2021

South Lampung is a regency with the capital of Kalianda which has an area of 2,007.01 km2 that dominates the agricultural area. Based on the data of corn crops in the South Lampung Regency Agriculture Office through BPS (Central Bureau of Statistics), showing several areas with corn crops that vary in number. Therefore, a grouping of potential corn-producing regions is required to know which areas produce large or small amounts of corn. The distribution of crops is usually done based on the name of the corn-producing sub-district. The K-Means clustering method is one of the data mining methods that is non-hierarchical clustering that groups data in the form of one or more clusters. Data that have the same characteristics are grouped in one cluster and the remaining is grouped into another cluster so that the data that is in one cluster has a small degree of variation. So the authors tried to apply the K-Means clustering method from the corn crop data of the last 2 years to produce feasibility information from each sub-district.
Comparison of Least Significant Bit, Pixel Value Differencing, and Modulus Function on Steganography to Measure Image Quality, Storage Capacity, and Robustness
Authors: Darwis D , Pamungkas N B , Wamiliana
Published: January 2021

Information security is an important aspect of information. The importance of the value of information in every aspect can result in attempts to transfer access or theft of data and information by unauthorized parties. One technique for securing data and information is by applying the digital image steganography technique. Many methods can be used in steganography, some of which are Least Significant Bit (LSB), Pixel Value Differencing (PVD), and Modulus Function (MF). Good steganography must produce a stego-image with an image quality that is not different from the original image or what is called a cover image and has the storage capacity to store confidential data and is resistant to robustness. The purpose of this study was to compare the LSB, MF, and PVD methods to serve as alternatives to the use of steganography techniques. The results of this study indicate that the LSB method has the best image quality compared to the MF and PVD methods. For storage capacity, the PVD algorithm has a better capacity than the LSB and MF methods. Meanwhile, the robustness of the LSB, PVD, and MF methods has resistance to cropping with a percentage of 10% at the bottom of the stego-image.
Implementation of Various Artificial Intelligence Approach for Prediction and Recommendation of Personality Disorder Patient
Authors: Sulistiani H , Muludi K , Syarif A
Published: January 2021

Personality disorder is known as chronic psychological disorders. It is a serious problem of the individual character and behavior that affect work, family and social life of a person. In many cases, the possibility of people do not realize that they have a personality disorder as a way of thinking and behaving seems natural to the patient, and the patient may blame others. To diagnose a personality disorder early, it is necessary to develop a system that is able to predict personality disorders and recommendation type of therapy patients should undergo. Artificial Intelligence is a technique that is very popular today. Various kinds of approaches and algorithms can be applied in the world of health, such as expert systems, neural networks and fuzzy logic. The aim of this study is to assess the artificial intelligence approach in predicting and recommending the type of therapy for patients with personality disorders.
Implementation of Fuzzy-based Model for Prediction of Prostate Cancer
Authors: Rusliyawati  , Muludi Kurnia , Syarif Admi , Wantoro Agus
Published: January 2021

Cancer is one of the leading causes of death worldwide. One type of cancer that causes death in the male population is prostate cancer. This disease occurs only in men because in women they do not have a prostate appearance. The aim of this study was to compare the accuracy of the model with the predictions of prostate cancer specialists. Prediction is made based on prostate specific antigen data, age, and patient prostate volume. The independent variables in this study were prostate specific antigen, age, and prostate volume. The dependent variable is the risk of prostate cancer using a fuzzy model. The novelty of this study is that the model has a low, moderate, high, and very high prostate cancer risk level output. In the previous article only PCR values were produced. The results show that the proposed fuzzy model provides a PCR value that is within the PCR interval predicted by a specialist doctor can be used properly to help diagnose and analyze the possibility of prostate cancer and is one of the considerations for doctors to decide whether or not a biopsy is needed for these patients.
Cytotoxic activity of methanol extraction of Avicennia marina and taurin in the HeLa cancer cells
Authors: Andriani S , Widiastuti E L , Nurcahyani N , rosa E , Busman H
Published: January 2021

The aim of study was to determine any anticancer potential from Avicennia marina leaf extract compare to taurine on cytotoxic and anti-proliferation activities against HeLa cervical cancer cell line by using the MTT method (3-(4, 5-dimethylthiazol-2-yl))-2, 5-diphenyltetrazolium bromide). The results indicated that methanol extraction of A. marina leaf as well as taurine did have cytotoxic and anti-proliferation effects on HeLa cell line with IC50 values of 321 ppm and 603 ppm 1000 ppm. While the doubling time value for anti-proliferation of A. marina leaf methanol extraction and taurine showed higher values than the control group (72.19 hours).
Inhibitory Study Of Cassava Leather Ethanol Extract As Natural Antimicrobial In Reducing Salmonella Sp. And Escherichia Coli On Contamination Chicken Meat (Gallus Domesticus)
Authors: Sartika D , Astuti S , Iswandari R
Published: January 2021

Chicken meat is a food product that is damaged easily and it’s a good medium for microbial growth. Therefore, it is needed a way to reduce the contamination of microbial pathogens. Cassava leather is a byproduct that contains an active compounds and it has a natural antimicrobial function to reduce pathogenic microbe contaminant. This study to determine the presence of natural antimicrobial activity against Escherichia coli and Salmonella sp. in chicken meat. The research was conducted using single factor with 7 treatment in Completely Randomized Block Design as many as 5 replications. Seven treatments of this research one positive control treatment (amoxicillin), and one treatment as control (96% ethanol). The results is cassava ethanol extract able to inhibit of Escherichia coli with the inhibitory diameter of 10.08 mm and Salmonella sp. with an inhibitory diameter diameter of 9.17 mm at a concentration extract of 100%, by extract concentrations of 80%, 60%, 40%, and 20%, with each inhibitory diameter 8.98 mm, 8.67 mm, 8.62 mm, 8.45 mm against Escherichia coli and 8.58 mm, 8.22 mm, 7.73 mm, 7.56 mm against Salmonella sp. The best concentration of cassava ethanol extract as a natural antimicrobial in chicken meat was 100% with total decrease to Escherichia coli 5.8 × 107cfu / g (69.05%) and total decrease of Salmonella sp by 4.0 × 107 cfu / g (41.17%).
The Potential of Temephos as Larvacide for Malaria Vector Control in Katibung Subdistrict, South Lampung
Authors: Setyaningrum E , Santoso B , Rouf A , Suryaningkunti J A
Published: January 2021

Lampung is one of provinces in Indonesia which still has malaria endemic areas in several subdistricts, including South Lampung District. In this subdistrict, the API recorded 0,212 in 2018 while in 2019 it decreased to 0,103. However, the potential of transmission still occurs due to the presence of extensive lagoons, swamps and puddle along the coast which support the proliferation of malaria vector in that area, one of which is Rangai Tri Tunggal Village, Katibung Subdistrict South Lampung. The purpose of this research is to find out the potential of temephos as a larvacide towards Anopheles sp. Mosquito larvae in Rangai Tri Tunggal Village, Katibung Subdistrict South Lampung District. The research used a quasi-experimental design by giving 1g/10 L of temephos to Anopheles sp. larvae at 10 breeding points of Anopheles sp. in Rangai Tri Tunggal Village, Katibung Subdistrict South Lampung started from August to September 2019. Larva density observations were carried out before and after the administration of temephos (day 21). The data analysis was administrated by using paired T-test. The result of the research showed that there is a significant difference (P<0,01) in the density of larvae before (23,8 heads/scoop) and after giving temephos (2,5 heads/scoop). The temperature at the sampling location ranged about 26-28°C with salinity 20 ppt, the types of aquatic plants are kale, mangroves, and water hyacinths and types of aquatic animals are fish, dragonflies and small snails. The conclusion is that temephos is worth to be considered as a larvacide for malaria vector control at Katibung Subdistrict South Lampung.
Identification of Virus Infection on Native Orchids in Liwa Botanical Garden
Authors: Mahfut  , Shafira H , Wahyuningsih S , Handayani T T , Sukimin
Published: January 2021

Liwa Botanical Garden is one of the regional botanical gardens in Indonesia with the theme “Indonesian Ornamental Plants”. At the present, disease infections are still a major obstacle in efforts to preserve and develop the potential natural orchids. Based on previous research, it is known that some individual orchids exhibit symptoms of viral disease infections, namely mosaic, chlorotic, streak, and necrosis. This research was conducted to determine the identification of against virus infections in Liwa Botanical Garden through a collection of samples that showed symptoms of infection, analysis of disease symptoms, and analysis of the level of disease resistance. The results showed the response of native orchids in Liwa Botanical Garden to viral infections showed symptoms in the form of necrotic black and chlorotic patches, yellowing leaves on orchids Coelogyne sp., Flickingeria sp., Calanthe sp., Trixspermum centipeda, Bulbophyllum sp. The type of orchid that shows the most symptoms is Flickingeria sp. a total of 8 samples. The type of natural orchid in the Liwa Botanical Garden which is most vulnerable to being infected with a virus is Flickingeria sp. with a disease intensity of 42%, while the type of orchid most infected virus is Coelogyne sp. with an intensity of 15%. The results of this activity are expected to be basic information in efforts to protect plants against diseases to support the application of conservation of natural orchids in the Liwa Botanical Garden.
Application of Xylanolitic Fungi Inoculum of Aspergillus Tubingensis R. Mossery in Bamboo (Bambusa Sp.) Litter Composting
Authors: Irawan B , Putri L F , Farisi S , Suratman
Published: January 2021

Bamboo is a plant that is easily found in various regions in Indonesia. Bamboo leaves are abundant and usually difficult to decompose naturally, so they are usually only burned. In fact, bamboo leaves can be a good source of organic material if processed properly. One way that can be used to overcome these problems is composting. The purpose of this study was to determine the effect of Aspergillus tubingensis (xylanolytic Fungi) inoculum with corn medium on the bamboo litter composting process. This research was conducted in a Completely Randomized Design (CRD) with 4 treatments consisting of Control (bamboo litter only), T1 (bamboo litter + 1% inoculum), T2 (bamboo litter + 1.5% inoculum), and T3 (bamboo litter + 2% inoculum) with 3 replications in each treatment. Chemical analysis is carried out at the 4th, 8th, and 12th weeks of composting. The result indicates that application of xylanolytic fungi inoculum of A. tubingensis gives dynamic results to C, N, P, and C / N ratio of bamboo litter compost during weeks 4, 8 and 12.
Nonrelativistic one-hadron-exchange k−p interaction model
Authors: Fadhlurahman H , Salam A , Fachruddin I
Published: January 2021

We have derived a nonrelativistic K−p interaction model as one-hadron-exchanges. The exchanged particles are the scalar meson σ, the vector mesons ω, ρ, the hyperons Λ, Σ, and the resonances Λ* (1600), Σ*(1385). Parameters in this model are determined by fitting to experimental data of spin-averaged differential cross section for kaon laboratory energy range of 51.27 MeV up to 900.64 MeV. The K-p scattering is calculated using a 3D technique without partial wave expansion.
Design of modulated infrared laser as a radiation source of portable photoacoustic spectroscopy
Authors: Apriyanto D K , Pauzi G A , Ayu H R
Published: January 2021

Photoacoustic spectroscopy can appl in various fields including in the fields of biology (measuring trachea volume and observing insect breathing patterns), medicine (a measurement of internal disease biomarkers through respiratory gases), environment (measuring NO2 gas in the environment near roads), and agriculture (measurement ethylene gas in postharvest fruit). The existing photoacoustic spectroscopy still has a large size and high operating costs, so it is necessary to design photoacoustic spectroscopy that is portable and low operating costs. In this research, designing an infrared diode laser that can be modulated using software using Visual Studio. There are two tests to see the characteristics of the devices made in this study, namely Arduino testing and testing of the software programs created. Arduino testing resulted in a calibration factor of fo
= 0.9068fi
+ 109.33. Meanwhile, software testing resulted in a calibration factor of fo
= 0.7343fi
+ 462.74. The two tests that have been carried out have different output results. The software output that is created has a smaller calibration factor than the direct output of the Arduino program.
Efficiency of natural folic acid in infant poured cream soup using mocaf for complementary feeding
Authors: Susilowati A , Aspiyanto  , Maryati Y , Lotulung P D N , Melanie H
Published: January 2021

Food additives using mocaf flour is a novelty as carrier of natural folic acid. This experiment work aims to find out optimization in adding mocaf to infant poured cream soup fortified by fortificant A (mixture of soy tempeh, nixtamalized yellow dent corn and fermented broccoli) and fortificant B (mixture of mung bean tempeh, nixtamalized yellow dent corn and fermented broccoli) on the whole compositions, particularly folic acid, characteristic, and efficiency for each component before and after pouring. Adding mocaf was conducted at concentrations of 0, 6, 12, 18, 24, and 30% (w/w, base formula of cream soup). The result of experiment showed that optimization for both folic acid in infant poured cream soup A and B were achieved at mocaf concentration of 24% (w/w, base formula of cream soup), which was able to increase folic acid 121.75% (1.22 folds) and 164.69% (1.65 folds), and total sugars 268.92% (2.7 folds) and 58.69% (0.59 fold), respectively compared with concentrations of folic acid and total sugars without adding mocaf (0%). In these conditions, both poured cream soup A and B gave efficiency on recoveries of folic acids of 46.62% and 51.34%, dissolved protein of 16.87% and 4.53%, total solids of 10.94% and 10.59%, total sugars of 57.86% and 39.73%, reducing sugars of 30.46% and 40.16%, respectively compared with concentration for each component without pouring which yields one (1) of dominant folic acid monomer with molecular weight 442.57 Da. and 2 folic acid monomers with MW of 442.12 Da. and 442.27 Da.. Meanwhile, particle size distribution at quantities of 10, 50, 90% were subsequently 8.94, 16,54, 125.02 μm and 9.54, 17.34, 106.49 μm, average particles size of 39.81 and 41.07 μm dominated by volatile compound as acetic acid of 14.86% and 27.97%, sucrose compound of 43.99% and 23.46%, methyl ester of 23.29% and 15.28%, ethanol of 14.10% and 11.67%, and fatty acids of 3.77% and 21.61%.
Adsorption Kinetic and Isotherm of Solution Pair of Methylene Blue and Crystal Violet by Algae-Silica-Magnetite Hybrid Adsorbent on Porphyridium sp. Algae
Authors: Permatasari D , Buhani  , Rilyanti M , Suharso
Published: January 2021

Algae-silica-magnetite hybrid (PSM) from Porphyridium sp. algae has been successfully synthesized using precursor tetraethyl orthosilicate (TEOS) and coating with magnetite particles (Fe3O4) via a sol-gel process. The resulting adsorbent was applied for adsorption of solution pair of methylene blue (MB) and crystal violet (CV). The result of the analysis using the Infrared Spectrometer (IR) showed that in the PSM adsorbent there is an organic groups derived from Porphyridium sp. algae while silanol and siloxane group derived from silica matrix. In addition, surface morphology analysis results using Scanning Electron Microscopy With Energy Dispersive X-Ray (SEM-EDX) showed PSM surface has more heterogeneous than algae-silica hybrid (PS). The adsorption of solution pair of MB and CV by PSM was done under the experimental conditions of adsorbent of 0.1 g, interaction pH of 8, contact time of 90 min, and adsorbate concentration of 0.5 mmol L−1. The adsorption kinetics data indicate that it tends to follow the pseudo second order model with a correlation coefficient (R2) of 0.989 and 0.965 respectively. While, the adsorption isotherm model tends to follow Freundlich model.
Isolation and Identification of Endophytic Fungi Associated with Indonesian Sesbania grandiflora Plant
Authors: Nurhidayat A , Noviany N , Setiawan A
Published: January 2021

In the present study, endophytic fungi associated with Indonesian Sesbania grandiflora plant were isolated and identified for the first time. The objective of this study was to report new data regarding the endophytic fungi found in S. grandiflora as one of Indonesian medicinal plant. Six isolates of endophytic fungi were isolated from the leaves, bark, seed, flower, and root of S. grandiflora collected from Labuhan Ratu, Kedaton, Bandar Lampung, Indonesia. Based on the prediction of their morphological characteristics visually, four isolates from all parts of plant were identified as Fusarium sp, while two isolates obtained from the bark and the seed were identified as Hormiscium sp and Penicillium sp, respectively. In addition, TLC profile result of secondary metabolites extract of endophytic fungi indicated that more than one major compound was observed. Furthermore, the antibacterial screening of isolated endophytic fungi did not show inhibition growth against resistant E. coli. However, the phytopharmacological study on the isolated fungi associated with S. grandiflora as well as their biological properties are still in progress. The results of this study revealed that S. grandiflora plant is reliable source of endophytic fungi for the future investigation.
Synthesis, characterization, and antioxidant activity of some organotin(IV) 2-nitrobenzoate using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) method
Authors: Nopitasari  , Suhartati T , Suharso  , Herasari D , Pandiangan K D , Hadi S
Published: January 2021

Synthesis, characterization, and antioxidant activity of diphenyltin(IV) di-2-nitrobenzoate (2), dibutyltin(IV) di-2-nitrobenzoate (4), and triphenyltin(IV) 2-nitrobenzoate (6) using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) method has been successfully carried out. All compounds were well characterized by some spectroscopy techniques of UV, IR, NMR and based on physical technique by microelemental analysis. The result showed that diphenyltin(IV) di-2-nitrobenzoate was the most active in the antioxidant activity test, with an IC50 value of 8.6 μg/mL compared to the other compounds in which the dibutyltin(IV) di-2-nitrobenzoate and triphenyltin(IV) 2-nitrobenzoate have IC50 values of 12.29 μg/mL and 27.28 μg/mL, respectively, which indicated that compounds 6 and 9 were categorized active antioxidant activity. However the IC50 values of these compounds were higher than the positive control, ascorbic acid with IC50 value of 0.66 μg/mL.
Synthesis, characterization and the antifungal activity test of some organotin(IV) benzoates
Authors: Hadi S , Irawan B , Yandri  , Suhartati T
Published: January 2021

In continuing search on the biological activity of the organotin compounds we are working with, We here reported the synthesis and the antifungal activity test of three organotin(IV) complexes of dibutyltin(IV) dibenzoate (3), diphenyltin(IV) dibenzoate (6) and triphenyltin(IV) benzoate (9). These three compounds were prepared by the reaction of dibutyltin(IV) dichloride (1), diphenyltin(IV) dichloride (4), and triphenyltin(IV) chloride (7) via dibutyltin(IV) oxide (2), diphenyltin(IV) oxide (5), and triphenyltin(IV) hydroxide (8) with benzoic acid. The product obtained in each step was characterized by UV, IR and NMR spectroscopies and also microelemental analysis. The antifungal activity test was carried out against Fusarium oxysporum strain. The results showed that the inhibition zone shown by these organotin(IV) benzoate were found by far much more active compared to the free benzoic acid, the starting materials 1, 4, 7, and the intermediate products, 2, 5 and 8. The inhibition zone of each of the compounds tested was compared with the control where the fungus alone was grown in the media. The results showed that triphenyltin(IV) benzoate (9) was the most active compound against the fungus and the minimum inhibitory concentration obtained was about 0.7 mM.
Docking Interaction of Chromium(III) Picolinate and Chromate Ion Compounds with Protein Tyrosine Phosphatase as Insulin Receptors
Authors: Ambarwati Y , Martoprawiro M A , Mulyani I , Ismunandar  , Onggo D
Published: January 2021

The Chromium(III) compounds have been shown to reduce glucose levels in type 2 diabetics, however, the role of chromium(III) in glucose metabolism cannot be clearly explained. Based on in vitro studies, there are two opinions regarding the mechanism of the role of chromium(III), the first opinion states that the chromium(III) that enters the body directly interacts with protein tyrosine phosphatase (PTP). Second opinion, chromium(III) which enters the body undergoes oxidation to become chromium(VI), and chromium(VI) interacts with PTP. To determine the mechanism that occurs, modeling using chromium(III) picolinate as a chromium(III) complex and chromate ion as chromium(VI) interacts with PTP. The structure optimization compounds was carried out using the Hartree-Fock computation method based on the 6-31G(d). The interaction study was studied using the Autodock Vina and ONIOM methods. The interaction results of chromium(III) picolinate docking interact with Leu(13), Ile(16), Ser(47), Trp(49), Asn(50), and Tyr(131) with interaction energy of - 7.00 kcal.mol−1. Chromate ion interacts with amino acids Leu(13), Gly(14), Ile(16), Cys(17) and Arg(18) with an interaction energy of -4.10 kcal.mol−1. The result of interaction energy of chromium(III) picolinate is lower than that of chromate ion, which indicates that the interaction of chromium(III) picolinate with PTP is better than chromate ion.
Transformation of multiple representation in real world physics problem solving
Authors: Murshed M. , Phang F. A. , Bunyamin M. A. H.
Published: January 2021

Multiple representation (MR) refers to the use of more than one way of representing ideas, concepts, and processes such as pictorial, graphical, numerical, oral and table. Studies in physics education also found that using MR increases achievement of problem solving among students when more emphasis was placed on qualitative representation. However, students often fail to exploit the advantages of MR or are difficult to transform between MR. In this study, the transformation of MR (TMR) carried out by the secondary school students in real-world physics problems was studied. The Think-Aloud Protocol (TAP) and retrospective semi structured interview (ProTRet) were used to provide more information about how the students use TMR in solving real-world problems. The analysis was qualitative in nature, focusing mainly on the process of the TMRs employed as well as the underlying reasons for their applications. The research data was analysed using constant comparative method (CCM) including open coding axial, coding and selected coding that generates a concept. It was found that there were three types of TMR created by the participants at the early stage of problem-solving, which could be used as an evaluation guide for process monitoring.
Diamond Touch (DT) based on hyperactive game in applying the concept of life science in early childhood education
Authors: Karnadi K , Sasmita K , Badrudin B , Palenewen E , Solihin S
Published: January 2021

Media DT based on this simple innovation hyperactive game is an alternative learning media used during the Covid-19 pandemic. This quantitative research aims to see the influence of these media on student learning outcomes. Forty-six primary school respondents were selected using a purposive sampling technique. The research instrument was a questionnaire and multiple choices. Data were analyzed by a simple regression test at a significance level of 0.05. The results showed the influence of hyperactive game-based DT media in increasing understanding of the concept of life science. The results of this study imply that the selection of attractive media is an important requirement in the learning process of the 21st century.
The content validity of the assessment instrument on the characters of wasaka in wetland environment physics learning
Authors: Wati M , Misbah M
Published: January 2021

Wasaka (waja sampai kaputing)is a philosophy widely known by the Banjar tribe. This philosophical value needs to be strengthened and maintained amongst students as part of character education. Therefore, an assessment instrument of the characterwasakawas developed to help teachers measure the values of religious, sincere, hard work, resilience, honesty, and persistence in students. This article aims to describe the validation of the contents ofwasakacharacter through assessment instrument as carried out using expert judgment method. There are 35 statement items assessed by 13 validators. Each statement item is examined by five assessment categories included in the expert validation sheets. The results of the assessments were analyzed using Aiken’s V equation to determine the level of validity of each statement item. With a validity standard of 0.75, there are 29 valid items and six invalid items. Furthermore, valid statements will be tested on students to determine the reliability of their measurements.
Trend exploration of the use of cognitive assessment techniques by high school science teachers
Authors: Ikhsanudin I , Nurtanto M , Atta H B , Novaliah  , Istiyono E
Published: January 2021

This study aims to describe the frequency of use of cognitive assessment techniques based on the length of the teaching of high school science teachers. The length of teaching indicates experiences that support teacher professionalism. A survey method was conducted on eighteen teachers from three outstanding schools. The research sample was determined purposively. Data collection was carried out using questionnaires and data analysis using descriptive statistics. The results showed that the dominant assessment technique used by high school science teachers was the written test, which was an average of 32 times in one semester. The group of teachers with a teaching length of 11 to 20 years used a more diverse range of assessment techniques than groups with other teaching lengths. Descriptively, it can be said that the frequency of use of various cognitive assessment techniques is related to the length of teaching teachers with the tendency to use written tests. However, the conclusions of this study cannot be generalized. Therefore, further research is needed with a representative research sample on the same topic. Besides, teachers and/or researchers can also investigate the combination of using assessment techniques to increase the effectiveness and efficiency of science learning.