1,812 research outputs found
A new species of Ribautiella (Myriapoda, Symphyla, Scolopendrellidae) from an Amazonian black-water inundation forest and notes on its natural history and ecology
Ribautiella amazonica is described from a black-water inundation forest near Manaus, Brazil. The genus is recorded for the first time for the Americas. R. amazonica was predominantly collected from the forest soil, mainly between 7 and 14 cm depth and is considered euedaphic. Data indicate, that advanced immature stages and adults withstand forest-inundation of 5 - 6 months duration in the soil and reproduce in the early part of the emersion period
Efficiency of network structures: The needle in the haystack
The modelling of networks formation has recently became the object of an increasing interest in economics. One of the important issues raised in this literature is the one of networks efficiency. Nevertheless, for non trivial payoff functions, searching for efficient network structures turns out to be a very difficult analytical problem as well as a huge computational task, even for a relatively small number of agents. In this paper, we explore the possibility of using genetic algorithms (GA) techniques for identifying efficient network structures, because the GA have proved their power as a tool for solving complex optimization problems. The robustness of this method in predicting optimal network structures is tested on two simple stylized models introduced by Jackson and Wolinski (1996), for which the efficient networks are known over the whole state space of parameter values.Networks, Optimal network structure, Efficiency, Genetic Algorithms
Sedimentological studies of the "Ilha de Marchantaria" in the Solimões/Amazon River near Manaus
Sedimentological studies on the Ilha de Marchantaria an island in the Amazon river near Manaus reveal the existence of four different structural main units. A: Sandy channel bars consisting of giant ripples constitute deposits for the formation of islands or newly formed areas of the Varzea. B: Gradual accumulation on the channel bars leads to the formation of point bar ridges which consist chiefly of small-scale ripples. C: Between point bar ridges of different ages there exist swales. During rising water level the river water flows from the downward side into the swales where finegrained sediments are deposited. D: Permanent lakes are formed mainly in the centre of the islands. During low water periods the lakes may be cut of from the river. During high water periods when the whole island is flooded by the river, additional sedimentation takes place especially in the upstream area of the island. There is however, extensive erosion of the banks on the upstream side of the island. By erosion of the upstream end and sedimentation processes on the downstream end the island moves slowly downstream
Sintesis dan Karakterisasi Carboxymethyl Cellulose (CMC) dari Selulosa Eceng Gondok (Eichhornia crassipes)
Abstrak. Penelitian ini tentang sintesis CMC dari variasi jenis pelarut selulosa masih belum banyak dilakukan. Penelitian ini bertujuan untuk mengetahui karakteristik CMC yang dihasilkan dari variasi jenis pelarut selulosa yang merupakan bahan dasar sintesis CMC. Penelitian ini terdiri dari 4 tahap, tahap pertama adalah persiapan sampel, tahap kedua adalah isolasi selulosa, tahap ketiga adalah sintesis CMC, dan tahap keempat adalah karakterisasi CMC . Preparasi sampel dilakukan dengan cara eceng gondok dibersihkan, dipotong, dan dikeringkan. Isolasi selulosa dilakukan dengan cara dewaxing, delignifikasi I, dehemiselulosa, delignifikasi II. Sintesis CMC dilakukan dengan cara alkalisasi, karboksimetilasi, netralisasi, dan pengeringan. Karakterisasi CMC dilakukan dengan uji warna, uji kadar air, uji DS, uji pH, uji kadar NaCl, dan uji kemurnian CMC. Karakteristik CMC terbaik diperoleh dari CMC dengan variasi jenis pelarut selulosa dengan H2O2 karena memiliki warna yang lebih putih (cerah) dibandingkan dengan CMC dari jenis pelarut selulosa yang lain, memiliki kadar air terendah sebesar 8,6625%, memiliki nilai DS terbaik 0,95, memiliki nilai pH yang mendekat netral sebesar 7,79, memiliki kadar NaCl yang mendekati CMC standar sebesar 1,2859%, dan memiliki kemurnian yang mendekati mutu 1 SNI sebesar 98,7141%.
Kata Kunci: Eceng Gondok, Isolasi Selulosa, Sintesis CMC, Karaketerisasi
Abstract. The research of CMC synthesis by variations type of cellulose solvent was rarely found. This research aim to investigate the CMC characteristics as the result from variation type of cellulose solvent which were the basic ingredient of CMC synthesis. The research was consists of four stages, the first stage was the preparation of samples, the second phase was cellulose insulation, the third stage was the synthesis of CMC, and the fourth stage was the characterization of CMC. Sample preparation was done by cleaning, cutting and drying the water hyacinth. Cellulose insulation was done by dewaxing, delignification I, dehemicellulose, delignification II. Synthesis CMC was done by alkalization, carboxymethylation, neutralization, and drying. Characterization of CMC was done by color test, water content test, DS test, pH test, NaCl content test, and purity of the CMC test. The best characteristic of CMC was obtained by using H2O2 as variation type of cellulose solvent because it produced a white color (brighter) of CMC than any other type of cellulose solvent, the lowest water content which is 8.6625%, the best DS value which is 0.95, pH value approach neutral 7.79, NaCl content 1.2859% which approach to CMC standard, and purity 98.7141% which approach SNI quality 1.
Keywords: Water Hyacinth, Cellulose Insulation, CMC Synthesis, Characterizatio
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Competing Next Generation Wireless Technologies
Wireless computing is facing a choice concerning the next telecommunication standard. Two of the new and competing protocol standards for local area and personal networking are 802.1 In and Ultra Wide Band. Each one has its own strengths and weaknesses and both will change wireless networking by dramatically increasing the transmission speed, the QoS and the security of the broadcast. Yet decisions have to be made about which protocol to adopt. The choice rests on a deeper understanding of each protocol, its evolution, compatibility and future direction. This paper analyzes these two competing protocols, discussing their performance and probability for success in the marketplace based on a wide range of criteria
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FDA’s Quality Systems Methodology at Pharmaceutical Manufacturing Sites
This research details the FDA\u27s quality systems methodology used in its inspection of biopharmaceutical manufacturers in the time period between 2003 and 2009. It analyzes the violations specified in FDA site inspection warning letters, reviewing their frequency and specificity. This analysis is an exploration into FDA activity in this sector, focusing particularly on finished pharmaceuticals, and serves as an initial evaluation of the FDA’s performance. In addition, the study pays particular attention to whether the FDA’s risk methodology has enhanced the overall inspection process and increased its quality assurance
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McNeil, Ft. Washington: FDA Case Study
This research analyzes the Food and Drug Administration’s (FDA) quality systems methodology through a detailed 12-year case study of McNeil Consumer Healthcare and its Ft. Washington, Pennsylvania manufacturing facility. This in-depth review, from 2000 to 2011, includes plant inspections reports, out-of-compliance findings, warning letters and a plant closure injunction. It then contrasts the specific findings of the McNeil case study with an analysis of overall FDA performance within the same sector of Finished Bio-Pharmaceuticals (BP). In addition, this case study pays particular attention to the role played by the FDA’s risk methodology in enhancing the overall inspection process and increasing its quality assurance
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A Risk Modeling Framework for the Pharmaceutical Industry
This conceptual paper seeks to advance a theoretical discussion on risk modeling and how it is used within the context of business process modeling. It discusses developments in risk modeling and then shows how they have been applied to the USA pharmaceutical industry. The pharmaceutical industry is a particularly interesting example in that it is bound on one side by stringent USA government mandates, and on the other by a risk adverse consumer population. A third aspect, the expanding cost structure of drug production and compliance, adds to the complexity of the problem. The discussion of risk in this paper applies mainly to regulated industries, and may be less applicable to more unregulated industry sectors. The important lesson for researchers is that a risk framework can play a significant part in business process modeling. The format for this paradigm may very well resemble a process repository, similar to those found in knowledge management systems
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Mobile Computing for Hospitals: Transition Problems
Mobile communication devices have an untapped potential to increase the quality of healthcare services. These devices can become the backbone for a new level of hospital service. This would include improved communications among medical and support staff and increased patient monitoring using a whole new generation of RFlDs. Yet, problems come with the introduction of new technology, some anticipated, some not. This paper develops several hospital scenarios depicting possible problem areas in the conceptualizing, planning and design of future mobile networks
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