Pemurnian Kondensat Hasil Pembuatan Gula Aren (Arenga Pinnata) Dengan Menggunakan Arang Aktif

Penelitian ini bertujuan untuk memproses kondensat hasil pengolahan gula aren melalui proses pemurnian dengan menggunakan adsorben arang aktif dari tempurung kelapa, menganalisis komponen kimia penyebab bau pada kondensat dengan teknik HPLC (High Performance Liquid Chromatography) serta menganalisis daya serap beberapa jenis arang aktif dari tempurung kelapa. Arang aktif yang digunakan memiliki daya serap yang bervariasi, yaitu 37-45%, 45-55%, 56-63% dan 70-85%. Hasil penelitian menunjukkan bahwa arang aktif dari tempurung kelapa dapat digunakan dalam proses pemurnian kondensat dan berdasarkan hasil analisis HPLC (Hig Performance Liquid Chromatography) terdapat tiga senyawa kimia yang menyebabkan bau pada konsendat. Arang aktif yang memiliki kapasitas adsorpsi yang besar yaitu arang aktif dengan daya serap 70-85% mampu menghilangkan bau hingga volume kondensat 4.497mL/g arang aktif

Uji Metode Olsen Dan Bray Dalam Menganalisis Kandungan Fosfat Tersedia Pada Tanah Sawah Di Desa Konarom Barat Kecamatan Dumoga Utara

Telah dilakukan penelitian untuk menentukan konsentrasi fosfat tersedia pada tanah sawah dan membandingkan dua metode ekstraksi fosfat, yaitu metode olsen yang menggunakan reagen NaHCO3 dan metode bray yang menggunakan reagen Bray dan Kurtz. Hasil ekstrak direaksikan dengan pereaksi pewarna fosfat bersama deret standar dan diukur absorbansinya menggunakan spektrofotometer pada panjang gelombang 693 nm. Hasil penelitian menunjukkan bahwa ekstrak fosfat tersedia dari metode Olsen menunjukkan hasil konsentrasi yang tinggi berturut–turut 422,861; 771,614; 1389,464; 1607,386; 821,591; dan 1139,925 ppm, sedangkan metode Bray menunjukkan hasil yang lebih rendah berturut-turut 16,102; 13,899; 11,307; 7,181; 7,183; dan 9,073 ppm. Reagen NaHCO3 pada sampel menyebabkan pH naik sehingga banyak fosfat yang terlepas, sedangkan reagen Bray dan Kurtz menyebabkan pH turun dan lebih sedikit fosfat yang terlepas. pH sampel yang bersifat asam menyebabkan metode Bray lebih cocok untuk digunakan daripada metode Olsen karena metode Bray spesifik untuk tanah asam, sedangkan metode Olsen dapat digunakan untuk tanah asam dan basa.A study aimed to determine the concentration of phosphate available to the rice field soil and to compare the two methods of phosphate extraction, which are Olsen that uses NaHCO3 reagent and Bray that uses Bray and Kurtz reagents, had been done. The extract was reacted with phosphate coloring reagent and standards and the absorbance was measured using spectrophotometer at a wavelength of 693 nm. The results showed that the extract of phosphate available using Olsen method showed higher value of concentrations which were 422.861; 771.614; 1389.464; 1607.386; 821.591; and 1139.925 ppm. On the other hand, Bray method showed a lower value which were 16.102; 13.899; 11.307; 7.181; 7.183; and 9.073 ppm. NaHCO3 increased the pH and more phosphate was released, while the Bray and Kurtz reagent decreased the pH and less phosphate was released. Due to the lower pH of the sample, Bray method is more suitable for acidic soils rather than Olsen method because of its specificity for acidic soil, while the Olsen method can be used for acidic and alkaline soil

Peatland Initiation, Carbon Accumulation, and 2 ka Depth in the James Bay Lowland and Adjacent Regions

Copyright © 2014 University of Colorado at Boulder, Institute of Arctic and Alpine ResearchPeatlands surrounding Hudson and James Bays form the second largest peatland complex in the world and contain major stores of soil carbon (C). This study utilized a transect of eight ombrotrophic peat cores from remote regions of central and northern Ontario to quantify the magnitude and rate of C accumulation since peatland initiation and for the past 2000 calendar years before present (2 ka). These new data were supplemented by 17 millennially resolved chronologies from a literature review covering the Boreal Shield, Hudson Plains, and Taiga Shield bordering Hudson and James Bays. Peatlands initiated in central and northern Ontario by 7.8 ka following deglaciation and isostatic emergence of northern areas to above sea level. Total C accumulated since inception averaged 109.7 ± (std. dev.) 36.2 kg C m–2. Approximately 40% of total soil C has accumulated since 2 ka at an average apparent rate of 20.2 ± 6.9 g C m–2 yr–1. The 2 ka depths correlate significantly and positively with modern gridded climate estimates for mean annual precipitation, mean annual air temperature, growing degree-days > 0 °C, and photosynthetically active radiation integrated over days > 0 °C. There are significantly shallower depths in permafrost peatlands. Vertical peat accumulation was likely constrained by temperature, growing season length, and photosynthetically active radiation over the last 2 ka in the Hudson Bay Lowlands and surrounding regions.US National Science Foundatio

Scrub typhus ecology: a systematic review of Orientia in vectors and hosts

Abstract Scrub typhus, caused by Orientia tsutsugamushi, is an important and neglected vector-borne zoonotic disease with an expanding known distribution. The ecology of the disease is complex and poorly understood, impairing discussion of public health interventions. To highlight what we know and the themes of our ignorance, we conducted a systematic review of all studies investigating the pathogen in vectors and non-human hosts. A total of 276 articles in 7 languages were included, with 793 study sites across 30 countries. There was no time restriction for article inclusion, with the oldest published in 1924. Seventy-six potential vector species and 234 vertebrate host species were tested, accounting for over one million trombiculid mites (‘chiggers’) and 83,000 vertebrates. The proportion of O. tsutsugamushi positivity was recorded for different categories of laboratory test and host species. Vector and host collection sites were geocoded and mapped. Ecological data associated with these sites were summarised. A further 145 articles encompassing general themes of scrub typhus ecology were reviewed. These topics range from the life-cycle to transmission, habitats, seasonality and human risks. Important gaps in our understanding are highlighted together with possible tools to begin to unravel these. Many of the data reported are highly variable and inconsistent and minimum data reporting standards are proposed. With more recent reports of human Orientia sp. infection in the Middle East and South America and enormous advances in research technology over recent decades, this comprehensive review provides a detailed summary of work investigating this pathogen in vectors and non-human hosts and updates current understanding of the complex ecology of scrub typhus. A better understanding of scrub typhus ecology has important relevance to ongoing research into improving diagnostics, developing vaccines and identifying useful public health interventions to reduce the burden of the disease.</jats:p

Enabling the freight traffic controller for collaborative multi-drop urban logistics: practical and theoretical challenges

There is increasing interest in how horizontal collaboration between parcel carriers might help alleviate problems associated with last-mile logistics in congested urban centers. Through a detailed review of the literature on parcel logistics pertaining to collaboration, along with practical insights from carriers operating in the United Kingdom, this paper examines the challenges that will be faced in optimizing multicarrier, multidrop collection, and delivery schedules. A “freight traffic controller” (FTC) concept is proposed. The FTC would be a trusted third party, assigned to equitably manage the work allocation between collaborating carriers and the passage of vehicles over the last mile when joint benefits to the parties could be achieved. Creating this FTC concept required a combinatorial optimization approach for evaluation of the many combinations of hub locations, network configuration, and routing options for vehicle or walking to find the true value of each potential collaboration. At the same time, the traffic, social, and environmental impacts of these activities had to be considered. Cooperative game theory is a way to investigate the formation of collaborations (or coalitions), and the analysis used in this study identified a significant shortfall in current applications of this theory to last-mile parcel logistics. Application of theory to urban freight logistics has, thus far, failed to account for critical concerns including (a) the mismatch of vehicle parking locations relative to actual delivery addresses; (b) the combination of deliveries with collections, requests for the latter often being received in real time during the round; and (c) the variability in travel times and route options attributable to traffic and road network conditions