Pemanfaatan Jerami Padi Sebagai Bioplastik Dengan Menggunakan Metode Perlakuan Pelarut Organik

Jerami padi memilki kandungan selulosa yang dapat dimanfaatkan sebagai bahan baku pembuatan bioplastik. Penelitian ini bertujuan untuk mensintesis bioplastik dari bahan baku jerami padi menggunakan perlakuan pelarut organik serta menganalisis pengaruh rasio massa pati dengan selulosa karakteristik produk bioplastik. Proses delignifikasi jerami menggunakan larutan etanol 5% dan 35% pada suhu 80oC selama dua jam. Bioplastik dibuat dengan rasio massa pati dengan selulosa sebesar 1:0,5; 1:1; dan 1:1,5. Karakterisasi menggunakan metode SEM, XRD, TG-DTA, uji tarik, uji transmisi uap, serta uji degradasi. Hasil penelitian menunjukkan bahwa proses delignifikasi menggunakan etanol menyebabkan peningkatan kadar selulosa serta kristalinitas jerami. Morfologi bioplastik menunjukkan permukaan yang tidak rata serta terdapat bagian matriks yang terpisah dengan fiber. Hasil TG-DTA menunjukkan pengurangan massa bioplastik sebesar 81,01% pada suhu 550oC. Hasil kuat tarik terbaik pada bioplastik yang dibuat dengan rasio massa pati dengan selulosa 1:0,5 pada konsentrasi delignifikasi etanol 35%. Nilai kuat tarik yang diperoleh sebesar 8,773 Mpa. Pengujian degradasi bioplastik dilakukan selama 10 hari diperoleh nilai % degradasi terbesar bioplastik adalah sebesar 99,9%. Rice straw contains cellulose which can be used as raw material for making bioplastics. This study aims to synthesize bioplastics from rice straw using organic solvent treatment and analyze the effect of the mass ratio of starch to cellulose on the characteristics of bioplastic products. The straw delignification process used 5% and 35% ethanol solution at 80oC for two hours. Bioplastics are made with a mass ratio of starch to cellulose of 1:0.5; 1:1; and 1:1.5. Characterization using SEM, XRD, TG-DTA methods, tensile test, vapour transmission test, and degradation test. The results showed that the delignification process using ethanol caused an increase in cellulose content and straw crystallinity. The morphology of the bioplastic shows an uneven surface and there are parts of the matrix that are separated from the fiber. The results of TG-DTA showed a reduction the mass of bioplastic by 81.01% at a temperature of 550oC. The best tensile strength results in bioplastics made with a mass ratio of starch to cellulose 1:0.5 at a delignification concentration of 35% ethanol. The tensile strength value obtained was 8,773 Mpa. The bioplastic degradation test was carried out for 10 days and the largest percentage of bioplastic degradation was 99.9%.

A Method for Calculating Elliptic Gear Transmission Efficiency Based on Transmission Experiment

Transmission efficiency is an important index to evaluate the transmission performance and energy consumption of gear transmission systems. To analyse the transmission efficiency of elliptic gears, the load torque fluctuation model of elliptic gear is established to analyse the influence of load torque of an elliptic gear transmission system on the torque of input and output. The torque data of input and output under different working conditions are obtained by conducting an elliptic gear transmission test. Finally, the transmission efficiency of the elliptic gear pair is obtained through the torque measurement data of the elliptic gear transmission test, and its variation law under different working conditions is analysed. The results show that the transmission efficiency of the elliptic gear transmission system changes constantly and presents an increasing trend with the increase of load torque and a decreasing trend with the increase of speed.

Use of Solar Panel in Design of Footpath

Solar footpath is a series of solar panel interlink to each other The outer layer of solar panel is covered with mild steel(MS). The tempered glass is attached to mild steel fabrication. Glass is tempered is such a way that it can bear up to 1 ton of load, various test are taken on glass like 1) ball drop test, 2) fragmentation test 3) light transmission test. Lithium battery is used to store the energy produce form the solar panel. The plus point of this design is that even if few panels get damage due to natural calamity other panel will still continue producing energy. Keywords: Photovoltaic cell, Tempered glass, Solar footpath

Preparation and Characterization of Gelatin-Based Films Cross-Linked by Two Essential Oils at Different Concentrations and Plasticized with Glycerol

Gelatin cross-linking has recently been discovered to be a very appealing method of producing gelatin-based films. The current research looks at various commercial gelatin (type B) films to improve their physical qualities. Bunium alpinum and bunium incrassatum essential oils (EOs) in two quantities (5% and 25%) were added to the films, which showed substantial biological activity (antibacterial, antioxidant, antihemolytic, and anti-inflammatory). According to electronic scanning microscopy, the basic gelatin matrix had changed and there were multiple dense spots on the cross-linked films. The particles appear to be more bonded in an isotropic form. Infrared spectroscopy cannot provide substantial accuracy on the new characteristics and chemical interactions formed due to the complex system of both gelatin and EOs. According to the UV transmission test results, adding EOs to gelatin films improves the barrier properties against UV rays and prevents UV light transmission. Finally, the swelling water test revealed that included EOs in the film composition reduce the film's swelling.

Investigation on the Influence Caused by Shield Tunneling: WSN Monitoring and Numerical Simulation

Traditional monitoring techniques are faced with the problems of low acquisition frequency and easy to be affected by the construction environment during the shield tunneling, which cannot meet the actual needs of timeliness monitoring of surrounding environmental impact on shield tunnel construction. Based on this actual demand, a wireless sensor network (WSN) system was used to monitor the response of shield tunnel segments and surrounding buildings during the shield tunneling in this study. According to the result of the signal transmission test, an optimization scheme of microelectromechanical system (MEMS) sensor layout is designed to improve the monitoring efficiency of the WSN system. Through the comparative analysis of WSN system monitoring data and traditional monitoring data, it is found that, with the increasing distance between the monitoring section and the tunnel face, the convergence value of tunnel lining clearance gradually tends to be stable, and the wireless monitoring results of transverse clearance convergence of the tunnel in this section are consistent with the overall deformation trend of the convergence gauge monitoring results. This study also simulated the shield tunneling adjacent buildings using a nonlinear finite element method. A parameter sensitivity analysis of the support pressure of the excavation face and the grouting pressure at the tail of the shield is carried out. The results show that the surface settlement can be reduced by properly increasing the grouting pressure and the support pressure of the excavation face. Moreover, increasing the support pressure of the excavation face has a better inhibition effect on the settlement of the surface soil than increasing the grouting pressure.

Characterization of banana bunchy top virus on Sumatra (Indonesia) wild banana

Rahayuniati RF, Hartono S, Somowiyarjo S, Subandiyah S, Thomas JE. 2021. Characterization of banana bunchy top virus on Sumatra (Indonesia) wild banana. Biodiversitas 22: 1243-1249. Banana bunchy top virus (BBTV) has been a major constrain on banana production worldwide. This virus infection is mostly found in banana cultivation. The study aimed to characterize the BBTV on Sumatra wild bananas. The survey to collect seeds and typical symptomatic samples had been done in 2017 and 2019 in West Sumatra, South Sumatra, and Bengkulu. The transmission test of the virus was conducted by using the viruliferous vector on four wild banana species, while the identity of BBTV confirmed by nucleotide sequences analysis using primer pairs of DNA R and DNA S. Musa acuminata subsp. sumatrana (AA) have been found naturally infected by BBTV. The transmission confirmed on M. acuminata subsp. longipetiolata, M. acuminata subsp. malacensis, M. acuminata subsp. halabanensis and Musa sp. with typical bunchy top symptoms. The incidence on test plants were 40%, 80% 20%, 20% and 20%, respectively. The virus infection on Sumatra wild bananas prolonged the incubation periods in comparison to cv Mas. BBTV of M. acuminata subsp. sumatrana is similar to the BBTV MK940788 and MN073184 from Sumatra. This is the first report of BBTV on Sumatra wild banana. The result can be used as a reference to study the resistance of the banana against BBTV.

Exploring the role and mechanism of COVID-19 apps in fighting the current pandemic

As COVID-19 pandemic spread worldwide, policies have been developed to contain the disease and prevent viral transmission. One of the key strategies has been the principle of “‘test, track, and trace” to minimize spread of the virus. Numerous COVID-19 contact tracing applications have been rolled around the world to monitor and control the spread of the disease. We explore the characteristics of various COVID-19 applications and especially the Aarogya Setu COVID-19 app from India in its role in fighting the current pandemic. We assessed the current literature available to us using conventional search engines, including but not limited to PubMed, Google Scholar, and Research Gate in May 2020 till the time of submission of this article. The search criteria used MeSH keywords such as “COVID-19,” “pandemics,” “contact tracing,” and “mobile applications.” A variable uptake of different COVID-19 applications has been noted with increasing enrolment around the world. Security concerns about data privacy remain. The various COVID-19 applications will complement manual contact tracing system to assess and prevent viral transmission. Test, track, trace, and support policy will play a key role in avoidance of a “second wave” of the novel coronavirus severe acute respiratory syndrome coronavirus 2 outbreak.

Seeds infection of Fusarium moniliforme in different Rice varieties grown in mid-hills of Nepal

Fusarium moniliforme is one of the important seed-borne fungi responsible for foot rot disease in rice. The study was conducted at the Plant Pathology Division of NARC, Khumaltar from July- December 2019 to find out the level of seed infection of F. moniliforme in different varieties of rice from mid-hills of Nepal. A total of 20 seed samples of different varieties of rice with 240 seeds of each sample were tested following a deep-freeze blotter method distributing 80 seeds per replication and maintaining 3 replications. Seed to seedling transmission test was carried out under screen house conditions. Two hundred seeds of each highly infected five varieties from laboratory test data were planted in eight pots, twenty-five seeds per pot, and categorized into four replications. Component plating was done to determine the location of F. moniliforme infection in a seed. Data analysis was done using STAR at a 5% level of significance. There was a significant difference among all the varieties. The highest incidence of F. moniliforme infection was found in seeds of Khumal-9 variety and lowest in Fan-10 variety. From seed to seedling transmission test, Khumal-4 variety was found highly susceptible to foot rot among the 5 varieties planted. Transmission percentage of disease from seed to seedling was found ranging from 16.19-72.31%. Equally, Component plating concludes that seed coat, as well as endosperm, was the location of F. moniliforme infection in rice seed. Foot rot being one of the serious diseases of rice at present time researches should be done more on this for its effective management and control. Seed health status testification before taking seeds to the field should be done so that timely control like seed treatment could be applied to control the outbreak of the disease in the field.