479 research outputs found
Preliminary Study In Finding Bioelastomer Based On Vegetable Oil: Dimer Acid Preparation
Dimer acid is the main material in the synthesis of bioelastomer. The preparation of dimer acid from vegetable oil such as crude palm oil and jatropha seed oil via Diels-Alder reaction were investigated. The dimer acid based vegetable oil was obtained by reacting vegetable oil with 12% by weight of acrylic acid and 0.05 – 0.15% by weight of iodine catalyst at temperature 191.25 – 247.5 oC for 1 – 2 hours. Dimer acids were analyzed using Fourier transform infrared spectroscopy, degree of acidity and acid value determination. The results show that the degree acidity (pH) of dimer acid from crude palm oil and jatropha seed oil were 2.18 – 2.35 and 2.46 – 2.56, respectively. The acid value of dimer acid from palm oil is 89.07 – 90.07 mg KOH/g sample and acid value of dimer acid from the jatropha seed oil is 63.80 – 80.43 mg KOH/g sample. Although the acid value is still lower than the commercial dimer acid (Empol 1016), the FTIR results showed that both dimer acids had some dicarboxylic acid functional groups as appeared in Empol 1016. So both vegetable oils have potential as a raw material for bioelastomer synthesis
Pengujian Kualitatif terhadap Jenis Koagulan dalam Bahan Olah Karet
Peningkatan mutu bahan olah karet (bokar) dapat dilakukan sejak awal proses pengolahan lateks menjadi bokar. Jenis koagulan merupakan salah satu parameter utama di dalam penentuan mutu bokar, selain tingkat kebersihan. Berdasarkan SNI bokar No. 06-2047-2002, koagulan yang dianjurkan untuk menggumpalkan lateks adalah asam format dan bahan penggumpal lain yang direkomendasikan oleh lembaga yang kredibel. Tetapi sebagian besar petani masih menggunakan koagulan non anjuran. Untuk itu perlu dilakukan suatu metode tertentu yang dapat mendeteksi bahan penggumpal bokar yang digunakan petani. Dengan metode ini, diharapkan petani akan menggunakan koagulan anjuran untuk meningkatkan mutu bokar. Dalam penelitian ini, metode yang digunakan untuk mendeteksi kandungan koagulan adalah pengujian secara kualitatif. Identifikasi dilakukan dengan cara mereaksikan serum atau air rendaman koagulum dengan pereaksi-pereaksi tertentu, kemudian diamati Perubahan pada campuran yang menandakan karakteristik dari ion-ion yang terkandung di dalam koagulan. Koagulan non anjuran seperti tawas, cukapara dan pupuk TSP dapat dideteksi dengan menggunakan pereaksi : 1) BaCl2, 2) campuran pereaksi NH4Cl dan NH4OH, 3) campuran pereaksi etanol dan asam sulfat dan 4) campuran pereaksi HNO3 dan ammonium molibdat. Hasil pengujian sensistivitas menunjukkan bahwa bahan penggumpal non ajuran dapat dideteksi pada dosis minimal 50 mL/L lateks (1 g/L lateks) untuk cukapara (asam sulfat), 25 mL/L lateks (0,5 g/L lateks) untuk pupuk TSP dan 75 mL/L lateks (1,5 g/L lateks) untuk tawas dengan konsentrasi masing-masing 2%. Pengujian kualitatif ini kemudian diaplikasikan untuk mengetahui kandungan ion pada koagulan “X”. Hasil pengujian menunjukkan bahwa koagulan “X” mengandung ion sulfat yang diduga berasal dari asam sulfat
Comparative study of the radius of sensitivity of the optical model potentials for Li+Ni and O+Ni
Radii of sensitivity were estimated for the Li+Ni system at
energies near the Coulomb barrier. For comparison purposes, such radii were
also estimated for stable O scattered from same target isotopes. The
elastic scattering data were analysed with folded real potential generated from
DDM3Y nucleon-nucleon interaction and an imaginary potential of volume
Woods-Saxon form. The most sensitive radii for O+Ni system are
found to be energy independent and close to the strong absorption radius. For
Li projectile, unlike its strongly bound counterpart, the crossing radius
increases with decreasing energy. However, no two crossing situation has been
observed for both Li+Ni and O+Ni systems at
the top of the barrier.Comment: Accepted for publication as a Brief Report in Physical Review C (4
pages, 5 figures
Problems and Prospects of Silk Industry in Bangladesh
Bangladesh is an underdeveloped and agro-based country. Silk industry is one of the important sectors of our national economy. It has a long and glorious past history but the growth and market share is not satisfactory of this industry to the national and global context. Thus it is an urgent need to mark the existing problem and future expectations of silk industry in Bangladesh. In our study we find out some problems of silk industry in Bangladesh like old technology, poor advertising, limited showroom, shortage of raw materials, inadequate capital, insufficient governmental facilities etc. We also find out some prospects of this industry like growth of sales and market share, low cost of labor, increasing demand, good geographical location, employment opportunity etc. So, it is essential to make effective plan and proper execution of that plan to get back the glorious position of our silk industry as well as to help the economical development of our country. Keywords: Silk, Mulberry, Industry Growth, Market Share, Technology, Quality Control
Development of Piezoelectric Nano- generator with Super-Capacitor
Harvesting mechanical energy from human motion is an attractive approach for obtaining clean and sustainable electric energy to power wearable sensors, which are widely used for health monitoring, activity recognition, gait analysis and so on. This paper studies a piezoelectric energy based device which conserve mechanical energy in shoes originated from human motion. The device is based on a on a pressure based energy generation. Besides, consideration is given to both high performance durability and build with repect to keeping the comfort in mind . The device provides an average output power of 1 mW during a walk at a frequency of roughly 1 Hz., a direct current (DC) power supply is built through integrating the device with a power management circuit
Recognition process of jamming signals superimposed on GSM-R radiocommunications
This paper explores an approach trying to recognize the presence of electromagnetic attacks on an equipment. Wireless communications are widely used in railway traffic management systems. Such systems are probably susceptible to be disturbed by malicious actions involving jammers. The general objective of this work is to develop a specific method enabling to detect and to recognize these types of interfering signals. This method could be used to involve adequate reactions in order to reduce the impact on the railway network. This paper focuses on the recognition method. It is based on accurate statistical models of signals generated by jammers. This work is carried out in the framework of the European project “SECRET” for SECurity of Railways against Electromagnetic aTtacks
Prescription to practice in hypertension: a community experience in central Kerala
Background: Control of blood pressure is a global challenge and non-adherence to hypertension medications is a public health concern. Patient, medication and system related factors can contribute to non-adherence. The study was to determine adherence to hypertension medications and to understand the barriers to adherence in an adult group in Pathanamthitta District of Central Kerala.Methods: A cross sectional study was conducted in a community setting in 2016, among 139 adults aged 30 years and above on treatment for hypertension for at least six months. Those with gestational hypertension, those having serious comorbid conditions and those unwilling to participate were excluded. The data sheet included basic demographic information and history related to hypertension. A content validated eight item questionnaire was used to assess reported adherence and scores classified level of adherence as good (8), moderate (6-<8) and poor (<6). The data was analyzed using SPSS. Chi square test of significance and multivariate regression analysis were done. P<0.05 was considered statistically significant.Results: The participants were in the age group 34-91 years, 50.4% belonging to 50-69 years, and 75.5% were females. Adherence to hypertension medications was good in 49.6%, moderate in 31.7% and poor in 18.7%. The most common factors reported to contribute to non-adherence were forgetfulness (70.5%), high cost of medications (51.8%), and symptom-free state (27.3%).Conclusions: Adherence was good in less than half the study participants and poor in almost one-fifth. Forgetfulness and high medication costs were the most commonly reported barriers. These findings highlight the importance of individuals, families and health service, joining hands to tackle the public health problem of non-adherence to hypertension medications
ANALISIS POLA DISTRIBUSI SPASIAL INDUSTRI KECIL DAN RUMAH TANGGA (IKRT) DI KECAMATAN GODEAN KABUPATEN SLEMAN BERBANTUAN SISTEM INFORMASI GEOGRAFIS (SIG)
Penelitian ini bertujuan untuk: 1) Mengidentifikasi karakteristik industri kecil dan rumah tangga yang terdapat di Kecamatan Godean, Kabupaten Sleman; 2) Menentukan pola distribusi spasial kelompok industri kecil dan rumah tangga unggulan di Kecamatan Godean, Kabupaten Sleman; dan 3) Menentukan pemetaan distribusi kelompok industri kecil dan rumah tangga unggulan di Kecamatan Godean, Kabupaten Sleman.
Penelitian ini merupakan penelitian deskriptif kuantitatif dengan berbantuan Sistem Informasi Geografis. Populasi dalam penelitian ini seluruh unit industri kecil dan rumah tangga di Kecamatan Godean. Teknik pengambilan sampel menggunakan proportional random sampling. Metode pengumpulan data yang digunakan adalah 1) observasi untuk memperoleh data sebaran industri kecil dan rumah tangga berupa titik-titik koordinat; dan 2) dokumentasi untuk memperoleh data karakteristik industri kecil dan rumah tangga yang didapatkan dari dinas-dinas terkait. Analisis data yang digunakan adalah analisis deskriptif kuantitatif, average nearest neighbor analysis, dan Location Quotient (LQ) analysis.
Hasil penelitian ini menunjukkan: 1) Terdapat 32 jenis kelompok industri yang beraneka ragam, rata-rata jumlah tenaga kerja yang terserap di setiap unit industri 1-9 orang, nilai investasi terbesar dihasilkan oleh kelompok industri genteng dari tanah liat/keramik dan terkecil dihasilkan oleh kelompok industri tempe kedelai, nilai produksi terbesar dihasilkan oleh kelompok industri genteng dari tanah liat/keramik dan terkecil dihasilkan oleh kelompok industri pakaian jadi (konveksi) dari tekstil, hasil penjualan terbesar diperoleh dari kelompok industri genteng dari tanah liat/keramik dan hasil penjualan terkecil diperoleh dari kelompok industri pakaian jadi (konveksi) dari tekstil; 2) Pola distribusi spasial industri kecil dan rumah tangga berdasarkan average nearest neighbor analysis termasuk ketagori pola mengelompok; dan 3) Industri kecil dan rumah tangga unggulan berdasarkan Location Quotient (LQ) Analysis tersebar di seluruh desa dengan jenis kelompok industri yang berbeda-beda.
Kata Kunci: Pola Distribusi Spasial, Industri Kecil dan Rumah Tangga
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