Model Operasional Rancangan Rantai Pasok Biodiesel dari Minyak Goreng Bekas di Kota padang

Sistem rantai pasok yang telah dirancang oleh Putra (2014) baru pada tahap desain atau strategi rancangan rantai pasok, belum pada tahap operasi rantai pasok. Tahap ini hanya memutuskan bagaimana rancangan struktur rantai pasok pada beberapa tahun ke depan, dan proses dari tiap tahap yang akan dilakukan dalam sistem rantai pasok secara umum. Sistem rantai pasok tersebut belum mempertimbangkan kebijakan operasional yang akan dilakukan oleh perusahaan dalam perencanaan produksinya. Perusahaan perlu mengeluarkan kebijakan untuk tiap tahapan operasional rantai pasok yang akan dilakukan sehingga menghasilkan sistem rantai pasok yang optimal, termasuk cara memanfaatkan segala sumber daya yang telah dirancang agar dapat mencapai tujuan dari sistem rantai pasok tersebut. Belum diketahui berapa banyak bahan baku yang akan dipasok dari suatu agen untuk memenuhi kebutuhan produksi di pabrik, berapa produksi optimal, dan berapa banyak biodiesel yang akan didistribusikan ke suatu distributor. Sehingga diperlukan optimasi terhadap model jaringan rantai pasok biodiesel dari minyak goreng bekas di Kota Padang yang dirancang tersebut agar dapat meminimasi total biaya operasional rantai pasok. Berdasarkan implementasi model yang telah dilakukan, model matematis yang dirancang telah menghasilkan solusi yang optimal. Karena total biaya operasional rantai pasok biodiesel yang dikeluarkan oleh perusahaan lebih kecil dari total biaya operasional rantai pasok kebijakan sebelumnya untuk 10 hari perencanaan produksi sebesar Rp 689.284,00 atau 0,186%. Komponen biaya produksi berkontribusi terhadap 65,625% dari total biaya dan komponen biaya pembelian minyak goreng bekas berkontribusi sebesar 32,617% terhadap total biaya. Sehingga perusahaan harus mempertimbangkan kedua komponen tersebut karena perubahan nilai komponen tersebut akan memberikan pengaruh yang besar terhadap perubahan total biaya operasional rantai pasok bagi perusahaan. Kata Kunci : Total Biaya, Biodiesel, Minyak Goreng Bekas, Model Matematis, Rantai Paso

An Overview of Champion International\u27s Benthological Water Quality Studies of the Clark Fork River

Benthological studies to define effluent impact have been conducted since 1956 at the pulp mill of Champion International Corporation near Missoula, Montana. The macroinvertebrates inhabiting riffle environments of the Clark Fork River are used to indicate water quality. The present study design uses the collection of replicate Surber samples from nine sites (three control plus six experimental) in a 20-mile river reach to characterize the fauna. Impact is determined by community analysis. Present and historical data show no significant mill impact upon taxa occurrence within the study area. Plecoptera, Ephemoroptera, Trichoptera and Diptera constitute the dominant groups at all study sites. Study data as recent as 1984 document a limited and localized increase in organism abundance relative to the mill. Stream enrichment is indicated. Overall water quality is altered only slightly by treatment wastewater from the mill

The River Benthos Record for Smurfit-Stone\u27s Missoula Mill -- Nearly a Half-Century of Clark Fork River Monitoring

The Missoula Mill of Smurfit-Stone Container discharges treated process water to the Clark Fork River near Frenchtown, Montana. Annual monitoring (1956 - present) of macroinvertebrate indicated river quality, is an integral part of the Missoula Mill\u27s environmental protection effort. Quantitative riffle benthos samples from ten sites (study reach = 22 miles) are taken during August. Impact is determined using control vs experimental comparisons of community descriptors including the biometrics subsets used in the calculation of the Montana Biological Integrity Index. Study results show significant background (upstream mill) enrichment in incremental amounts over the period 1960 through the late 1980\u27s, presumably a product of growth in the Clark Fork, Blackfoot, and Bitterroot drainages. Mill related impact throughout this same period, also expressed as enrichment was limited and localized to the zone of initial dilution. Recent study results (1995 - 1999) generally show either continuation, or a slight decline, in overall enrichment of the system relative to the Missoula Mill\u27s treated effluent

Predicting the Drug Release Kinetics of Matrix Tablets

In this paper we develop two mathematical models to predict the release kinetics of a water soluble drug from a polymer/excipient matrix tablet. The first of our models consists of a random walk on a weighted graph, where the vertices of the graph represent particles of drug, excipient and polymer, respectively. The graph itself is the contact graph of a multidisperse random sphere packing. The second model describes the dissolution and the subsequent diffusion of the active drug out of a porous matrix using a system of partial differential equations. The predictions of both models show good qualitative agreement with experimental release curves. The models will provide tools for designing better controlled release devices.Comment: 17 pages, 7 figures; Elaborated at the first Workshop on the Application of Mathematics to Problems in Biomedicine, December 17-19, 2007 at the University of Otago in Dunedin, New Zealan

Pertunjukan Simuntu dan Tari Kreasi Karya Yeni Eliza dalam Sepekan Kesenian Tradisi di Nagari Andaleh Baruh Bukik

This article discusses the Sepekan Kesenian Tradisi, an event for the creativity and potential of Andaleh Baruh Bukik's young generation in building their nagari through performing arts activities, games and traditional performances. Two of the forms of creativity that are produced and displayed in Sepekan Kesenian Tradisi are the new creation of dance and the Simuntu performance. Through the application of qualitative research methods with a dance ethnology approach, data on the creativity and potential of the Andaleh village youth are described and analyzed using the concepts of creativity, biography, and folk festivals. Sepekan Kesenian Tradisi was then followed by the holding of various games and performing arts, which were basically the result of the creativity of the nagari youth, where Yeni Eliza took on the role of initiator of activities and creator of new dance creations which became the material for the activities.Keywords: Traditional Arts Week; Andaleh Baruh Bukik; Simuntu; Creative Dance; festivalAbstrakArtikel ini membahas tentang Sepekan Kesenian Tradisi, sebuah ajang kreativitas dan potensi generasi muda Andaleh Baruh Bukik dalam membangun nagari mereka melalui kegiatan seni pertunjukan, permainan dan pertunjukan tradisional. Dua di antara bentuk kreativitas yang dihasilkan dan ditampilkan dalam Sepekan Kesenian Tradisitersebutadalah seni tari kreasi baru dan pertunjukan Simuntu. Melalui penerapan metode penelitian kualitatif dengan pendekatan etnologi tari, data-data tentang kreativitas dan potensi generasi muda nagari Andaleh dideskripsikan dan dianalisis menggunakan konsep kreatifitas, biografi, dan festival rakyat.Penelitian menunjukkan bahwa pertunjukan Simuntu, berperan penting sebagai daya tarik kegiatan,di mana kehadirannya menjadi awal mula keramaian.Proses kegiatan Sepekan Kesenian Tradisi kemudian dilanjutkan dengan digelarnya berbagai permainan dan seni pertunjukan, yang pada dasarnya adalah hasil kreatifitas pemuda nagari, di mana Yeni Eliza mengambil peran sebagai inisiator kegiatan dan kreator tari kreasi baru yang menjadi materi kegiatan.Kata Kunci: Sepekan Kesenian Tradisi; Andaleh Baruh Bukik; Simuntu; Tari Kreasi; festiva

Determination of Stable Co-Amorphous Drug-Drug Ratios from the Eutectic Behavior of Crystalline Physical Mixtures

Co-amorphous drug–drug systems have been developed with the overall aim of improving the physical stability of two or more amorphous drugs. Co-amorphous systems often show good physical stability, and higher solubility and dissolution rates compared to their crystalline counterparts. The aim of this study is to determine if eutectic mixtures of two drugs can form stable co-amorphous systems. Three drug–drug mixtures, indomethacin–naproxen (IND−NAP), nifedipine–paracetamol (NIF−PAR), and paracetamol–celecoxib (PAR−CCX), were investigated for their eutectic and co-amorphization behavior as well as their physical stability in the co-amorphous form. The phase diagrams of the crystalline mixtures and the thermal behavior of the co-amorphous systems were analyzed by differential scanning calorimetry. The solid-state form and physical stability of the co-amorphous systems were analyzed using X-ray powder diffractometry during storage at room temperature at dry conditions. Initial eutectic screening using nifedipine (NIF), paracetamol (PAR), and celecoxib (CCX) indicated that IND−NAP, NIF−PAR, and PAR−CCX can form eutectic mixtures. Phase diagrams were then constructed using theoretical and experimental values. These systems, at different drug-to-drug ratios, were melted and cooled to form binary mixtures. Most mixtures were found to be co-amorphous systems, as they were amorphous and exhibited a single glass transition temperature. The stability study of the co-amorphous systems indicated differences in their physical stability. Comparing the phase diagrams with the physical stability of the co-amorphous mixtures, it was evident that the respective drug–drug ratio that forms the eutectic point also forms the most stable co-amorphous system. The eutectic behavior of drug–drug systems can thus be used to predict drug ratios that form the most stable co-amorphous systems

Predicting Crystallization of Amorphous Drugs with Terahertz Spectroscopy.

There is a controversy about the extent to which the primary and secondary dielectric relaxations influence the crystallization of amorphous organic compounds below the glass transition temperature. Recent studies also point to the importance of fast molecular dynamics on picosecond-to-nanosecond time scales with respect to the glass stability. In the present study we provide terahertz spectroscopy evidence on the crystallization of amorphous naproxen well below its glass transition temperature and confirm the direct role of Johari-Goldstein (JG) secondary relaxation as a facilitator of the crystallization. We determine the onset temperature Tβ above which the JG relaxation contributes to the fast molecular dynamics and analytically quantify the level of this contribution. We then show there is a strong correlation between the increase in the fast molecular dynamics and onset of crystallization in several chosen amorphous drugs. We believe that this technique has immediate applications to quantify the stability of amorphous drug materials.JS and JAZ would like to acknowledge the UK Engineering and Physical Sciences Research Council for funding (EP/J007803/1).This is the final version of the article. It first appeared from ACS at http://dx.doi.org/10.1021/acs.molpharmaceut.5b0033

Influence of Solvent Composition on the Performance of Spray-Dried Co-Amorphous Formulations

Ball-milling is usually used to prepare co-amorphous drug–amino acid (AA) mixtures. In this study, co-amorphous drug–AA mixtures were produced using spray-drying, a scalable industrially preferred preparation method. The influence of the solvent type and solvent composition was investigated. Mixtures of indomethacin (IND) and each of the three AAs arginine, histidine, and lysine were ball-milled and spray-dried at a 1:1 molar ratio, respectively. Spray-drying was performed at different solvent ratios in (a) ethanol and water mixtures and (b) acetone and water mixtures. Different ratios of these solvents were chosen to study the effect of solvent mixtures on co-amorphous formulation. Residual crystallinity, thermal properties, salt/partial salt formation, and powder dissolution profiles of the IND–AA mixtures were investigated and compared to pure crystalline and amorphous IND. It was found that using spray-drying as a preparation method, all IND–AA mixtures could be successfully converted into the respective co-amorphous forms, irrespective of the type of solvent used, but depending on the solvent mixture ratios. Both ball-milled and spray-dried co-amorphous samples showed an enhanced dissolution rate and maintained supersaturation compared to the crystalline and amorphous IND itself. The spray-dried samples resulting in co-amorphous samples were stable for at least seven months of storage