ABSTRAK. Penggunaan wafer ransum komplit mengandung limbah kopi pada itik peking dilakukan dengan tujuan untuk mengetahui berat akhir dan persentase karkas. Materi penelitian yang digunakan adalah itik peking umur 1 hari (DOD) sebanyak 96 ekor dibagi dalam 4 perlakuan dan 3 ulangan. Ransum yang digunakan satu bulan pertama adalah ransum komersil, dan satu bulan terakhir wafer ransum komplit mengandung limbah kopi. Ransum perlakuan yang diberikan adalah: P0 = Wafer ransum komplit 0% limbah kopi (kontrol), P1 = Wafer ransum komplit 2,5% limbah kopi, P2 = Wafer ransum komplit 5% limbah kopi, dan P3 = Wafer ransum komplit 7,5% limbah kopi. Parameter yang diamati: bobot hidup, bobot karkas, bobot potongan karkas, persentase karkas, dan persentase potongan karkas. Penelitian ini menggunakan Rancangan Acak Lengkap. Data dianalisis dengan analysis of variance dan dilanjutkan dengan Uji Duncan. Hasil penelitian menunjukkan penggunaan limbah kulit kopi sebagai bahan penyusun ransum itik peking dalam bentuk wafer ransum komplit berpengaruh nyata terhadap bobot akhir. Penggunaan limbah kulit kopi 2,5% dalam ransum secara signifikan (P<0.05) meningkatkan bobot karkas dan potongan karkas. Dapat disimpulkan penggunaan limbah kulit kopi sebanyak 2,5% sebagai bahan penyusun wafer ransum komplit tidak memberi pengaruh negatif terhadap bobot badan akhir, persentase karkas dan potongan karkas itik peking. (Carcass percentage of peking duck feed wafer complete ration containing of coffee waste) ABSTRACT. This research was conducted to study the effectiveness of wafer complete ration containing coffee waste on the final body weight and carcass percentage. The study used 96 DOD Peking duck. Completely Randomized Design (CRD) consisting of 4 treatments and 3 replications. Rations used during the first month was a commercial ration, and then subsequently wafer complete ration of coffee waste given as treatments; P0 = wafer complete ration contained 0% of coffee waste (control), P1 = wafer complete ration 2,5% of coffee waste, P2 = wafer complete ration 5% of coffee waste, and P3 = Wafer complete ration 7,5% of coffee waste. The observed variables were: final body weight, carcass weight, carcass percentage, carcass component weight, and carcass component percentage. Collected data was analyzed by ANOVA and followed by Duncan’ Multiple Range Test if there was a significant different between treatments. The results showed wafer complete ration containing coffee waste was significantly (P< 0.05) effect on final body weight. Feed containing 2,5 % of coffee waste significantly (P<0.05) effect on carcass weight and carcass percentage. It is concluded that no negatif effect of wafer complete ration containing 2,5 % coffee waste on final body weight and carcass percentage of peking duck.
An experimental method for estimating the tangential contact stiffness of contact interface with controlled contact asperities is discussed. The tangential contact stiffness is analyzed from the shift of certain eigenmode frequency of the system resulting from the changes in the density of contact asperities and the application of normal force. The results show that for the case of contact combination with 189 contact asperities, the corresponding eigenmode frequency shifted from 1.01 kHz at normal force of 19 N to 1.64 kHz at normal force of 148 N. This shift corresponds to the increase of tangential contact stiffness from 34.08 MN/m at normal force of 19 N to 67.44 MN/m at normal force of 148 N. It is found that the corresponding eigenmode frequency and its shift were affected by the density of contact asperities as well as the normal force. In the case of contact combination with 397 contact asperities, the corresponding eigenmode frequency shifted from 2.36 kHz at normal force of 49 N to 3.9 kHz at normal force of 153 N, indicating the increase of the tangential contact stiffness from 93.91 to 140.73 MN/m. A simple power relationship is proposed to explain the quantitative relationship between the eigenmode frequency shift and the tangential contact stiffness value.
In this work, a novel anti-corrosion water-based lubricant is prepared. Carboxymethyl cellulose and Uncaria Gambir Extract, all in powder form, were dispersed in water. Corrosion, stability, and tribology test with pin-on-disk reciprocating tribometer were studied. The newly obtained lubricants were designated as Uncaria Gambir (UG), i. e. UG0 (0% volume Uncaria Gambir extract in Carboxymethyl cellulose, UG1 (1% volume Uncaria Gambir extract in Carboxymethyl cellulose, and UG2 (2% volume Uncaria Gambir extract in Carboxymethyl cellulose). The addition of Uncaria Gambir Extract into Carboxymethyl cellulose solution delivered good stability, low corrosion rate, and stable friction coefficient. UG1 has the best stability (no sedimentation), corrosion, and tribological performance. After a one-hour friction test, UG2showed the best performance in terms of CoF, indicated by a 7.6% CoF reduction, compared to UG0. This finding indicates the potential of Uncaria Gambir Extract as an additive for an anticorrosive water-based lubricant for machining application.
In this paper, a fundamental mechanism for creep-groan generation is investigated by adopting a simple yet effective caliper-slider experimental model. Contact condition, which is a function of three parameters, namely normal force, contact roughness, and material combination, is connected with the creep-groan phenomenon in terms of contact stiffness. Creep-groan generation is determined by analyzing the frequency characteristic of the generated vibration acceleration when the sliding commences due to a simultaneous application and release of force in the tangential and normal directions, respectively. As per the obtained results, creep-groan occurrence or absence in the employed experimental model may be classified into three regions based upon the value of the contact stiffness, i.e., occurrence, non-occurrence, and mixed regions. The results also indicate that creep-groan occurrence in this caliper-slider experimental model can be avoided by controlling the value of contact stiffness in an effective manner.
Sistem Pengeringan dengan metode hybrid merupakan sistem pengeringan yang menggunakan dua atau lebih sumber energi untuk proses penguapan air. Pengering hybrid pada penelitian ini menggunakan sumber energi matahari dengan bantuan solar kolektor dan energi bahan bakar gas. Penelitian ini merupakan alternatif teknologi untuk kasus pengeringan ikan. Tujuan dari penelitian ini adalah untuk meningkatkan temperatur udara panas ruang pengering hybrid, melakukan optimalisasi waktu pengeringan dan menghitung kadar air pada ikan. Penelitian ini dilakukan di halaman Fakultas Teknik Universitas Syiah Kuala. Hasil pengukuran temperatur tertinggi ruang pengering tanpa bahan/ikan dengan menggunakan kolektor surya adalah 43 o C dengan intensitas cahaya matahari tertinggi 915 W/m 2 , setelah menggunakan metode hybrid temperatur tertinggi ruang pengering dengan kondisi ada bahan/ikan meningkat sampai 67 o C dengan intensitas cahaya matahari tertinggi 908 W/m 2. Pengeringan menggunakan energi hybrid relatif lebih singkat yaitu 8,5-13 jam sedangkan pengeringan secara tradisional membutuhkan waktu selama 3 hari dengan kondisi cuaca cerah dan intensitas cahaya matahari yang tinggi. Tingkat penguapan kadar air mencapai 30,25%-38,18 % untuk ikan karang/ikan kakap merah, dan 53,30%-57,13% untuk ikan teri.
This research is aimed at studying the stability and tribology properties of the polyol ester oil- (POE-) based biolubricant mixed with various filler loadings from microparticle of TEMPO-oxidized bacterial cellulose (NDCt) as an additive and sorbitan monostearate (Span 60) as a surfactant. Morphology, rheology, and tribology tests were conducted. The addition of NDCt and Span 60 to pure POE as a base fluid showed elevated viscosity, lower value of coefficient friction (COF), and a remarkable decrease in the wear rate (WR). The presence of 0.6 wt% NDCt and 1.8 wt% Span 60 in POE (N2S4) decreased the COF value by 79% in comparison to POE. At room temperature, this N2S4 biolubricant sample showed a higher thermal conductivity by 4% and lower WR value by 49% compared to POE. This study introduced the preparation of the ecofriendly biolubricant filled with NDCt improving the tribology properties remarkably.
A map that shows the necessary condition for avoiding the generation of low-frequency stick-slip of a creep groan is introduced. The map is obtained as a result of comprehensive investigation employing a novel caliper-slider experimental model. According to the map, creep groan generation is controlled by two dimensionless parameters, designated as stiffness ratio, Sr, and low-frequency stick-slip index, Ls. Stiffness ratio, Sr, is the ratio of structure stiffness to the stiffness at contact interface and Ls is an index formed by various parameters such as normal force, sliding velocity, and difference between static and kinetic coefficients of friction. On the experimental model, creep groan generation can be avoided if one or both of the following conditions is fulfilled: (a) stiffness ratio, Sr, larger than 40 (Sr > 40) and/or (b) low-frequency stick-slip, Ls, index larger than 400 (Ls index > 400). It is expected that the map can be used as a useful guideline for avoiding the generation of similar phenomenon on a real brake system.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.