Mechanical Properties of Natural Fiber Composite Made of Indonesian Grown Sisal

Sisal fiber is one of the most widely used natural fibers and is very easily to be cultivated. Sisal is considered to be indigenous to central and south America. According to FAO, nearly 4.5 million tons of sisal fiber is produced every year throughout the world. Brazil and Tanzania are the two main producing countries. Indonesia and Thailand are two of the South East Asian countries that also produces sisal. This paper presents a comprehensive experimental work on the fabrication and characterization of epoxy composite reinforced with Indonesian grown sisal. The sisal fiber was specifically grown in Lombok, Indonesia. The composite laminate was fabricated using vacuum bagging process. The characterization processes were conducted to evaluate the the mechanical properties which includes tensile, flexure, shear and compressive properties of such composites. The results showed that the mechanical properties of the examined sisal-epoxy composite in this study has a comparable properties with some of the previous reported studies. The epoxy composite reinforced with unidirectional oriented sisal (UOS) fiber has the tensile, flexural, shear and compressive stress of 40.25 MPa, 62.16 MPa, 23.26 MPa and 60.88 MPa, respectively. While the epoxy composite reinforced with randomly oriented sisal (ROS) fiber has the tensile, flexural, shear and compressive stress of 22.52 MPa, 51.5 MPa, 22.34 MPa and 49.12 MPa, respectively. The results have clearly shown that epoxy composite reinforced with unidirectional oriented sisal fiberhas a better mechanical properties than epoxy composite reinforced with randomly oriented sisal fiber

Histologi Dorsal Horn Dari Spinal Cord Mencit Yang Mengalami Nyeri Inflamasi Akibat Induksi Cfa (Completed Freuds Adjuvant) Setelah Pemberian Gabapentin Dan Baclofen

Pain is a multidimentional experience, generally most of chronic disease followed by pain incidence. Chronic pain can be caused by inflammation or neuropathic condition and change the imbalance of N-methyl-D-aspartate receptor 2B (NR2B) subunit. This research was an observation of the influence of gabapentin and baclofen to dorsal horn histology in inflammatory-induced chronic pain. Fourty mice Balb-C strain were divided into 8 groups i.e sham, negative control, gabapentin at three different doses (10, 30, 100 nmol) and baclofen at three different doses (1, 10, 30 nmol). Inflammatory condition was induced by intraplantar injection of CFA (Completed Freuds Adjuvant). Gabapentin and baclofen were given intrathecally once a day for seven consecutive days, at a week after CFA injection. Latency time toward thermal stimulus was measured on days 0, 1, 3, 5, 7, 8, 10, 12 and 14 after CFA injection. Paw thickness at the ipsilateral site was also measured on days 0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12 and 14 after CFA injection. Histology of the dorsal horn of spinal cord tissue was examined by haematoxylline-eosin staining. The result showed that intrathecal injection gabapentin and baclofen significantly increased latency time of mice toward thermal stimulus compared to negative control. Whereas gabapentin and baclofen administration could decrease inflammatory cell, vasodilatation and increase neuron forming of the dorsal horn histology compare to negative control. The conclusion of this research was gabapentin and baclofen administration had antinociceptic effect by increased latency time toward thermal stimulus and recoved histology of dorsal horn from mice with inflammatory painKeywords : Inflammation, CFA, Gabapentin, Baclofen, Dorsal horn.AbstrakNyeri merupakan pengalaman yang multidimensional. Umumnya kebanyakan penyakit kronik selalu disertai dengan nyeri. Nyeri kronik dapat disebabkan oleh inflamasi maupun neuropati dengan patofisiologi yang berhubungan dengan aktivitas reseptor N-methyl-D-aspartate (NMDA) subunit 2B (NR2B). Sampai saat ini pengobatan nyeri kronik menjadi tantangan. Obat yang bekerja sebagai agonis GABA seperti gabapentin dan baclofen dilaporkan mempunyai peranan penting dalam penghambatan proses nyeri. Penelitian ini dilakukan untuk mengetahui pengaruh pemberian gabapentin dan baclofen terhadap histologi dorsal horn pada keadaan nyeri kronik akibat inflamasi. Hal ini bertujuan untuk menjelaskan bagaimana gabapentin dan baclofen dapat digunakan sebagai terapi pada nyeri kronik. Empat puluh mencit dibagi menjadi delapan kelompok, yaitu sham, kontrol negatif, gabapentin dosis 10, 30 dan 100 nmol/mencit serta baclofen dosis 1, 10 dan 30 nmol/mencit. keadaan inflamasi diinduksi oleh injeksi intraplantar CFA (Completed Freuds Adjuvants). Gabapentin dan baclofen diberikan secara intratekal sehari sekali selama tujuh hari, pada hari ketujuh setelah induksi CFA. Waktu ketahanan terhadap stimulus panas diukur menggunakan hot/cold plate pada hari ke-0, 1, 3, 5, 7, 8, 10, 12 dan 14 setelah induksi. Tebal plantar diukur pada hari ke-0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12 dan 14 setelah induksi. Respon nyeri diamati secara visual seperti mendekatkan kedua tungkai kaki ke depan, menjilat tungkai kaki ke depan, gerakan meliuk, berusaha melompat keluar hot/cold plate,dan menghentakkan tungkai belakang. Histologi bagian dorsal horn dari spinal cord diamati menggunakan pewarnaan haematoxyllin-eosin. Pemberian gabapentin dan baclofen meningkatkan waktu ketahanan terhadap stimulus panas secara signifikan dibandingkan kontrol. Secara histologi, pemberian gabapentin dan baclofen menurunkan sel inflamatori, menurunkan vasodilatasi dan meningkatkan bentukan neuron pada dorsal horn dari spinal cord dibandingkan dengan kontrol. Kesimpulan dari penelitian ini adalah pemberian gabapentin dan baclofen meningkatkan waktu ketahanan terhadap stimulus panas serta memperbaiki histologi dorsal horn dari spinal cord mencit dengan nyeri inflamasi setelah induksi CFA.Kata kunci : Nyeri inflamasi, CFA, Gabapentin, Baclofen, Dorsal hor

EXPERIMENTAL STUDY OF LOCAL SOLID WOOD POST-FIRE BEHAVIOUR

When wood structures are exposed to high temperatures, they will decompose to provide a char layer and pyrolysis zone, an insulating material that inhibits further degradation. This experimental study aims to determine the char thickness and pyrolysis of solid wood exposed to fire for 30, 45, and 60 minutes. The post-fire shear strength has also been evaluated. The solid woods were locally from Nusa Tenggara Island, namely Jati Putih, Bajur, and Rajumas. According to the Indonesian National Standard of the heating curve for structures, the temperature growth was SNI-1741: 2008. Obtained The char layer's highest average thickness was within 60 minutes of combustion with the highest temperature of 1055oC. The char layer for Jati Putih, Bajur, and Rajumas are 2.12 mm, 7.89 mm, and 6.53 mm. Meanwhile, the pyrolysis layers are 8.78 mm, 9.13 mm, and 14.82 mm, respectively, for Jati Putih, Bajur, and Rajumas. Besides, the post-fire shear strength of all wood species shows an increase in shear strength in the core. Wood can still sustain the load during a fire because there is a char layer preventing the core section from immediately exposed to the fire.  

Application of Electro-Oxidation Method for Treatment of Dye Textile Wastewater Using Stainless Steel Electrode: Study of Electrolyte Concentration Effect to Color Removal

The increasing number of textile industries has created a new problem of environmental pollution from waste produced. Entering of concentrated wastewater that containing of complex organic compounds to agricultural land and rivers has caused loss to humans or the environment. Treatment of dye textile wastewater by electro-oxidation method using stainless steel electrode has been done. This research consists of several stages: analysis of electrode composition with SEM-EDX, electrolysis of wastewater at variation of electrolyte concentration and analysis of electrolyte concentration effect to color removal percentage of wastewater. The result shows that the electrode composition consisted of iron, chromium, nickel and silica with the main composition of iron in the amount of 72.2%. After electrolysis on variations of electrolyte concentration and analysis of color removal percentage of wastewater, obtained that the largest of color removal percentage on the use of electrolyte concentration of 3% in the amount of 98.81

Studi eksperimental terhadap porositas dan hambat alir udara pada komposit penyerap suara

In this paper, we present a comprehensive analytical and experimental investigation for the determination of the air flow resistivity and porosity of sound absorber composite. The ratio of the volume fraction of fiber and polyester resin is 15, 25, 35, 55 and 65 (%).The dimensions of the absorbent composite sample are 29 mm x 20 cm (diameter x thickness). Porosity and Air flow resistivity of composites have been investigated. The results showed that the porosity of the composites increased with increasing amount of fiber due to the interface between fiber and resinless dense. In contrast, the air flow resistivity values are lower with a denser resin and fiber interface

Compressive Properties of Tropical Natural Fibers Reinforced Epoxy Polymer Composites

Fiber reinforced plastics composites are particularly valued for their high tensile strength. Other mechanical properties, especially compressive strength is often overlooked during the characterization process. In fact, the comparatively low compression strength of some composite reduces their promising application. This paper presents the experimental investigation on the compressive strength of epoxy polymer composites reinforced by natural fibers of sisal, jute, hemp and bamboo grown in tropical area. The natural fiber composites were prepared using vacuum bagging method and the fibers were treated with alkali treatment prior to further processing. The results showed that the average values of compressive strength obtained in this work ranged from 31.69 MPa to 86.64 MPa. Those results indicate that the obtained compressive strength of natural fibers composites investigated in this research were comparable to the results of previous work, which ranged from from 16.75 MPa to 108.07 MPa

Flexural strength of sandwich panel with lignocellulosic composites intermediate layer: a statistic approach

In this study, three different types of lignocellulosic composite materials have been incorporated in sandwich panel structure as an intermediate layer. The experiment was statistically designed based on single factor analysis scheme. The results of experiments have been analyzed using analysis of variance (Anova) followed by Tukey's, Fisher's and Dunnet's tests to obtain the information of how significant those materials contribute to the flexural strength of sandwich panel structure. The total number of samples tested was 48 beams. The results show that the introduction of lignocellulosic composites materials, that are hardboard, medium density fibre (MDF) and plywood, has significantly improved the flexural strength of sandwich panel. The range of improvement contributed by the presence of lignocellulosic composites intermediate layer was around 100 – 150% for samples with balsa core and 130-150% for samples with polystyrene core. The result of this study shows the potential of lignocellulosic composite material to be developed further for producing more sustainable sandwich panel