Effects of Brick Burning on Microbial Biomass and C/N Ratio in Selected Soil Profiles in the Eastern Region of Bangladesh

The pH values in the profiles of unburnt (agricultural land) soils were found to increase as a function of soil depth and burning (400 to 1000℃) of the soils increased average pH by 8%. The average sand content of the burnt (soil around brick kilns) soil profiles was increased by 245%, while 39 and 36% decreased the silt and clay contents. Soil organic carbon (Corg) in the unburnt soils (0-20 cm) at different agro-ecological zones in the eastern region of Bangladesh ranged from 0.8 and 1.4%, whereas the content of microbial biomass carbon (Cmic) in the studied unburnt soils ranged between 5 and 7% of the total Corg, suggesting that the microbial biomass releasing considerable amounts of carbon in soil while burning of the soils drastically reduced this contribution to about 1%. The values of soil Cmic in the unburnt soils were approximately 2 to 6 times higher in the topsoils than the subsoils (20-60 cm). Variable rainfall, temperature and soil fertility had an overriding influence, which was reflected by the average minimum (276 μg g(-1)) and maximum (439) amounts of soil Cmic in Moulvibazar and Cox' Bazar sites. The Cmic decreased upon soil burning by 92% of its original average value (346 μg g(-1)) in the soil profile of up to 100 cm. Burning of topsoils strikingly increased the Corg/Cmic ratio by about 6 to 9 times, while reduced the C/N ratio by about 1.5 to 2.5 times. The average loss of Corg, available and total N due to burning of the soils were 66, 72 and 44% (increase over average content of unburnt soil: IOAC), respectively, which suggests that the burning of the soils offset the essential roles of soil microorganisms, reduced soil fertility and soil microbial contribution

Performance Analysis of Solar Adsorption Cooling System - Effect of Position of Heat Storage Tank

An insulated storage tank has been added with adsorption cooling system run by solar heat collected by CPC panel. It has been expected and seen that the storage tank has a vital contribution in the performance of the chiller. The storage tank is connected with a solar heat driven single stage two bed basic adsorption chillers activated with silica gel-water pair in two ways. The tank is connected in such a way that (i) the solar collectors supply hot water to the desorption bed, the outflow of the desorber is collected in the reserve tank. The reserve tank supplies water to the collector and complete the heat transfer cycle. (ii) The solar collector supply hot water which is collected in the storage tank first and then supplied to the desorber. The outflow of the desorber is carried to the collector again. Comparative studies have been conducted at the steady state for both of the systems with heat storage. It has been observed that the system is robust with design (i) while with design (ii) performance enhances beyond the sunset time with heat storage

Analisis Kelayakan Ekonomi Berbagai Sistem Sadap pada Panel Bo Tanaman Karet (Studi Kasus Kebun Batujamus Jawa Tengah)

Fluktuasi harga karet merupakan fenomena yang tidak dapat dihindari, namun pebisnis karet senantiasa berusaha bertahan agar biaya produksi rendah dan produktivitas kebun meningkat. Salah satu USAha yang dilakukan adalah penurunan frekuensi sadap. Penelitian ini bertujuan untuk menganalisis kelayakan ekonomi berbagai sistem sadap di panel BO dengan variasi frekuensi sadap dan stimulansia yang diharapkan mampu menurunkan biaya penyadapan dan penggunaan tenaga penyadap. Penelitian dilaksanakan di Kebun Batujamus milik Perusahaan negara mulai Oktober 2015 hingga Oktober 2016. Penelitian disusun dengan Rancangan Acak Kelompok Lengkap dengan 11 perlakuan sistem sadap dan 3 ulangan. Analisis anggaran parsial digunakan untuk menilai kelayakan ekonomi. Hasil penelitian menunjukkan bahwa sistem sadap yang layak untuk diterapkan adalah sistem sadap S/2d3.ET2.5%.Ga.1.m/3, S/2 d3.ET2.5%.Ga.1.2w, S/2 d3.ET4.0%.Ga.1.2w, S/2 d4.ET4.0%.Ga.1.2w dan S/2 d4.ET5.0%.Ga.1.2w. Adapun sistem sadap S/2 d3.ET5.0%.Ga.1.2w, frekuensi sadap d5 dan d6 tidak layak secara ekonomi

Peningkatan Produksi dan Analisis Finansial pada Buka Sadap dengan Lilit Batang > 45 Cm untuk Menghadapi Harga Karet Rendah

Salah satu upaya untuk menghadapi kondisi harga jual karet yang rendah adalah dengan meningkatkan produktivitas untuk menekan harga pokok dan menghindari kerugian. Peningkatan produktivitas dalam jangka panjang dapat melalui pengoptimalan keragaan tanaman terutama lilit batang dengan menunda buka sadap. Perbedaan kriteria buka sadap di Indonesia dengan negara penghasil karet lain diduga turut menyebabkan perbedaan produktivitas yang terjadi. Penelitian ini bertujuan untuk mengetahui peningkatan laju pertumbuhan lilit batang sebelum dan sesudah tanaman disadap, peningkatan produktivitas dan laba/rugi akibat adanya penundaan buka sadap. Penelitian dilakukan di areal tahun tanam 2010, Galardowo, Kebun Getas, PTPN IX Jawa Tengah dan mulai dilaksanakan pada bulan Oktober 2015 (akhir TBM V) hingga 2017. Rancangan penelitian yang digunakan adalah Rancangan Acak Lengkap dengan faktor tunggal yaitu kelas lilit batang. Parameter yang diamati yaitu lilit batang dan tebal kulit awal, pertumbuhan lilit batang dan tebal kulit tiap bulan, volume lateks, kadar karet kering (K3), dan produksi karet kering per pohon, serta taksasi/proyeksi produksi untuk bulan berikutnya. Poduktivitas tersebut selanjutnya digunakan menghitung analisis finansial buka sadap pada tiap kelas lilit batang. Metode analisis finansial pada penelitian ini menggunakan analisis R/C ratio. Hasil penelitian menunjukkan bahwa buka sadap yang dilakukan pada lilit batang lebih besar dari kriteria normal menunjukkan lebih besar laju pertumbuhan lilit batang dan tebal kulitnya serta lebih tinggi produksinya sehingga keuntungan atau nilai R/C ratio pada saat TM 1 juga semakin besar

Kombinasi Sistem Sadap Frekuensi Rendah dan Penggunaan Stimulan untuk Optimasi Produksi dan Penurunan Biaya Penyadapan di Panel Bo

Fluktuasi harga karet sering terjadi di bisnis karet. Kondisi tersebut menjadi masalah apabila harga karet rendah namun tidak diimbangi dengan kenaikan produksi dan penurunan biaya produksi. Penelitian ini bertujuan mendapatkan kombinasi sistem sadap terbaik yang menurunkan biaya penyadapan dan meningkatkan produksi. Upaya penurunan biaya produksi dilakukan melalui penerapan frekuensi sadap (d3, d4, d5 dan d6) dengan perbedaan konsentrasi stimulan (ET 2.5%, 3.0%, 4.0% dan 5.0%) disadap pada panel B0-2 secara SKB. Rancangan penelitian yang digunakan RAKL dengan 10 pohon dan diulang 3 kali. Penelitian dilaksanakan mulai Oktober 2015 hingga Oktober 2016 di Kebun Batujamus, Afdeling Kedung Sumber, PTPN IX.Klon yang digunakan PB 260, tahun tanam 2000 jarak tanam 6x3 m. Hasil penelitian menunjukkan bahwa produksi pada penyadapan d3 stimulan 2.5% dan 4.0% memiliki produktivitas lebih tinggi, dibandingkan kontrol. Meskipun demikian hasil uji statistik menunjukkan tidak beda nyata. Kombinasi frekuensi sadap rendah dan perlakuan stimulan dapat diterapkan ketika harga karet rendah dan kesulitan tenaga sadap. Semakin rendah frekuensi sadap maka semakin rendah biaya penyadapan. Frekuensi sadap d6 merupakan sistem sadap yang paling rendah biayanya dan menurunkan biaya 58-59% dari kontrol (d2). Untuk aplikasi di lapangan, sebaiknya mempertimbangkan produktivitas yang diperoleh dari berbagai sistem sadap, karena produktivitas berpengaruh terhadap pendapatan dan keuntungan kebun. Seperti halnya frekuensi sadap d3, meskipun hanya mampu menurunkan biaya 25-28% dari d2, namun mampu menghasilkan produksi tertinggi dibandingkan dengan frekuensi sadap lainnya. Sedangkan frekuensi sadap d4 potensial diterapkan pada perkebunan karet dengan permasalahan kelangkaan tenaga sadap, karena memiliki produksi lebih tinggi dan biaya lebih rendah dibandingkan kontrol

Phenotypic Characterization of a Major Quantitative Disease Resistance Locus for Partial Resistance to Phytophthora sojae

Major quantitative disease resistance loci (QDRLs) are rare in the Phytophthora sojae (Kaufmann and Gerdemann)–soybean [Glycine max (L). Merr.] pathosystem. A major QDRL on chromosome 18 (QDRL-18) was identified in PI 427105B and PI 427106. QDRL-18 represents a valuable resistance source for breeding programs. Thus, our objectives were to determine its isolate specificity and measure its effect on yield and resistance to both P. sojae and other soybean pathogens. We characterized near isogenic lines (NILs) developed from F7 recombinant inbred lines heterozygous at QDRL-18; NILs represent introgressions from PI 427105B, PI 427106, and susceptible ‘OX20- 8’. The introgressions from PI 427105B and PI 427106 increased resistance to P. sojae by 11 to 20% and 35 to 40%, respectively, based on laboratory and greenhouse assays, and increased yield by 13 to 29% under disease conditions. The resistant introgression from PI 427105B was also effective against seven P. sojae isolates with no isolate specificity detected. Based on quantitative polymerase chain reaction assays, NILs with the susceptible introgression had significantly higher relative levels of P. sojae colonization 48 h after inoculation. No pleiotropic effects for resistance to either soybean cyst nematode or Fusarium graminearum were detected. This information improves soybean breeders’ ability to make informed decisions regarding the deployment of QDRL-18 in their respective breeding programs

‘‘Lozenge’’ contour plots in scattering from polymer networks

We present a consistent explanation for the appearance of “lozenge” shapes in contour plots of the two dimensional scattering intensity from stretched polymer networks. By explicitly averaging over quenched variables in a tube model, we show that lozenge patterns arise as a result of chain material that is not directly deformed by the stretch. We obtain excellent agreement with experimental data

Effect of n-hexane extract of Nigella sativa on gentamicin-induced nephrotoxicity in rats

The present study investigated whether the administration of the n-hexane extract of the Nigella sativa Linn. (kalajira) ameliorates gentamicin-induced nephrotoxicity in rats. Gentamicin (100 mg/kg/day for 7 days) was administered and nephrotoxicity was evaluated biochemically (significantly decreased reduced glutathione in renal cortex and significantly increased serum creatinine and serum urea) and histologically (moderate degree of proximal tubular damage). The n-hexane extract of N. sativa (5 mL/kg/day) was administered as pre-, post- and concomitant treatment for 7 days in the nephrotoxic rats. Statistically significant amelioration in all the biochemical parameters supported by significantly improved renal cortical histology was observed in the n-hexane extract of N. sativa treated nephrotoxic rats, which was more evident in the post-treatment group than the pre-treatment and the concomitantly-treated group. It is suggested that some ingredients contained in the n-hexane extract of N. sativa effected in ameliorating the signs of nephrotoxicity and that the specific active principle of the n-hexane extract of N. sativa responsible for this amelioration if obtained, would be more useful

Modelling of Multi-Agent Systems: Experiences with Membrane Computing and Future Challenges

Formal modelling of Multi-Agent Systems (MAS) is a challenging task due to high complexity, interaction, parallelism and continuous change of roles and organisation between agents. In this paper we record our research experience on formal modelling of MAS. We review our research throughout the last decade, by describing the problems we have encountered and the decisions we have made towards resolving them and providing solutions. Much of this work involved membrane computing and classes of P Systems, such as Tissue and Population P Systems, targeted to the modelling of MAS whose dynamic structure is a prominent characteristic. More particularly, social insects (such as colonies of ants, bees, etc.), biology inspired swarms and systems with emergent behaviour are indicative examples for which we developed formal MAS models. Here, we aim to review our work and disseminate our findings to fellow researchers who might face similar challenges and, furthermore, to discuss important issues for advancing research on the application of membrane computing in MAS modelling.Comment: In Proceedings AMCA-POP 2010, arXiv:1008.314