Volume of Vortex Moduli Spaces

A gas of $N$ Bogomol'nyi vortices in the Abelian Higgs model is studied on a compact Riemann surface of genus $g$ and area $A$. The volume of the moduli space is computed and found to depend on $N, g$ and $A$, but not on other details of the shape of the surface. The volume is then used to find the thermodynamic partition function and it is shown that the thermodynamical properties of such a gas do not depend on the genus of the Riemann surface.Comment: LaTex file, 17 pages. To appear in Comm. Math. Phy

Methyl esters selectivity of transesterification reaction with homogenous alkaline catalyst to produce biodiesel in batch, plug flow, and continuous stirred tank reactors

Selectivity concept is essential in establishing the best operating conditions for attaining maximum production of the desired product. For complex reaction such as biodiesel fuel synthesis, kinetic studies of transesterification reaction have revealed the mechanism of the reaction and rate constants. The objectives of this research are to develop the kinetic parameters for determination of methyl esters and glycerol selectivity, evaluate the significance of the reverse reaction in transesterification reaction, and examine the influence of reaction characteristics (reaction temperature, methanol to oil molar ratio, and the amount of catalyst) on selectivity. For this study, published reaction rate constants of transesterification reaction were used to develop mathematical expressions for selectivities. In order to examine the base case and reversible transesterification, two calculation schemes (Case 1 and Case 2) were established. An enhanced selectivity was found in the base case of transesterification reaction. The selectivity was greatly improved at optimum reaction temperature (60 C), molar ratio (9 : 1), catalyst concentration (1.5 wt.%), and low free fatty acid feedstock. Further research might explore the application of selectivity for specifying reactor configurations

Methyl esters selectivity of transesterification reaction with homogenous alkaline catalyst to produce biodiesel in batch, plug flow, and continuous stirred tank reactors

Selectivity concept is essential in establishing the best operating conditions for attaining maximum production of the desired product. For complex reaction such as biodiesel fuel synthesis, kinetic studies of transesterification reaction have revealed the mechanism of the reaction and rate constants. The objectives of this research are to develop the kinetic parameters for determination of methyl esters and glycerol selectivity, evaluate the significance of the reverse reaction in transesterification reaction, and examine the influence of reaction characteristics (reaction temperature, methanol to oil molar ratio, and the amount of catalyst) on selectivity. For this study, published reaction rate constants of transesterification reaction were used to develop mathematical expressions for selectivities. In order to examine the base case and reversible transesterification, two calculation schemes (Case 1 and Case 2) were established. An enhanced selectivity was found in the base case of transesterification reaction. The selectivity was greatly improved at optimum reaction temperature (60 C), molar ratio (9 : 1), catalyst concentration (1.5 wt.%), and low free fatty acid feedstock. Further research might explore the application of selectivity for specifying reactor configurations

Measurement of NO2 indoor and outdoor concentrations in selected public schools of Lahore using passive sampler

Higher levels of NO2 are a danger to human health especially for children. A seven day study was carried to find out the ambient concentrations of NO2in 27 schools of Lahore with the help of passive samplers. In each school three sites were selected, viz: laboratory, corridor and outdoors. After 7 days exposure the tubes were subjected to spectrophotometric analysis. Results showed that the maximum values measured in laboratory, outdoor and corridors were 376µg/m3 , 222µg/m3 and 77µg/m3 . Minimum values for laboratory, outdoor and corridors were 10µg/m3 , 20µg/m3 and 8µg/m3 . Factors affecting these values were laboratory activities and proximity to main roads. These values were significantly higher than the standard values defined by EPA. Therefore children in schools were at risk of developing health complications

Facilitating statistical software using SS E Guide / N. Ahmad, A.M. Nasir, and S. Masrom

The process of data analysis for the purpose of research is very important and this process sometimes is very complicated, especially for researchers who do not have any statistical basis. We developed specific software to analyze the data. The problem occurs when students are not familiar with such software. The most important process in the analysis of data is to run the correct analysis. For example, analysis of mean between samples can be done either using parametric or non-parametric test. If students choose the wrong analysis, this will lead to the inappropriate conclusion. The second problem face by the students is how to use statistical software. Some software will produce output even if the method chosen is not suitable. So this E Guide application is intended to facilitate two things: how to choose the appropriate analysis data and how to use statistical software to get the correct output. E Guide also provides interpretation of output from example provided

Pengendalian Terpadu Penyakit Kudis (Sphaceloma Batatassaw.) pada Ubijalar

Penyakit kudis yang disebabkan oleh Sphaceloma batatas merupakan penyakit penting dan banyak menimbulkan kerugian hasil yang cukup besar di negara-negara produsen ubijalar (Ipomoea batatas)di Asia, Australia, negara-negara Caribia, kepulauan Pacific dan Amerika latin. Di Indonesia penyakit kudis telah tersebar di sentra produksi ubijalar di Jawa,Bali, Sumatera dan Papua. Kehilangan hasil ubijalar akibat serangan penyakit kudis dapat mencapai 30%, tergantung varietas, umur tanaman pada saat terinfeksi dan kondisi lingkungan. Umumnya penyakit kudis berkembang didataran tinggi dan terutama pada musim hujan. Pengendalian terpadu penyakit kudis dapat dilakukan dengan mengkombinasikan beberapa cara pengendalian yang saling kompatibel dalam satu paket pengendalian yaitu: menanam varietas yang tahan (Muaratakus, Cangkuang, Sewu, Sari, Sukuh, Kidal, Papua Salosa dan Sawentar), menggunakan bibit sehat atau mencelup bibit dalam larutan fungisida Benomyl atau Mankozeb selama 15 menit, rotasi tanam dengan tanaman yang bukan inang jamur seperti tanaman kacang tanah, kedelai, jagung atau padi, sanitasi lahan dengan memusnahkan bekas tanaman yang terinfeksi dan menyemprot fungisida Benomyl (400 g ba/ha), Chlorotalonil 1300 g ba/ha, Captafol 1520 g ba/ha, fentin hidraxide 300 g ba/ha, tembaga oxiklorida 1500 g ba/ha dan Mankozeb 1500 g ba/ha, atau pestisida nabati (4 g/100 ekstrak bawang merah) apabila diperlukan

Investigating Asphaltenes Composition in Crude Oil Samples using Iatroscan TLC-FID Method.

This research was carried out to investigate the percentage composition of asphaltenes by Iatroscan analysis using Thin Layer Chromatography-Flame Ion Detection method (Iatroscan TLC-FID) The percentage composition of asphaltenes by Iatroscan TLC-FID method was compared with the weight% of asphaltenes precipitated. The results from the two methods nearly agreed with each other which revealed that the amount of asphaltene recovered by precipitation is analogous to Iatroscan analysis carried out prior to precipitation. The insignificant difference observed between the two results could be associated to some slight unavoidable experimental and analytical errors which were slightly encountered and instantly addressed. Based on the results obtained from Iatroscan analysis and % composition by weights of asphaltenes recovered, the non-degraded oil tagged 8676 was observed to comparatively have higher asphaltene composition (1125 mg, 11.22 %) than its counterpart which is very slightly degraded oil and tagged 6661 (608.5 mg, 6.085 %). This is not commonly reported in literature. Probably, this indicates that biodegradation may possibly not increase asphaltene composition of oil as widely reported.Keywords: Asphaltenes, Biodegradation, Iatroscan TLC-FID, Oi

Penerapan Model Pembelajaran Discovery Learning untuk Meningkatkan Keterampilan Psikomotor Fisika Siswa Kelas X SMA Seri Rama Ylpi Pekanbaru

This study is aims at determine learning outcome physic students psychomotor skills application Discovery Learning model at class X Seri Rama YLPI senior high school at Pekanbaru using model Discovery Learning at geometrical optics materials. The research was conducted from March 2015 through June 2015 by 38 research subjects at X1 as experimental group and 27 students at Xz as control group in Seri Rama YLPI senior high school at Pekanbaru. This research is a form of pre-experimental design Intact Group comparasion. The research instrument is physic psychomotor skill achievment test arrange of application aspect adaption. Psychomotor skills learning outcomes studied cover aspects of reading tools, measuring angles with a bow, and planned experiments obtained absorption with good category for its effectiveness in class experiments and categorized effective, whereas for the control class obtained absorption with good enough category and for its effectiveness categorized enough effective. The result of the research indicated of 79,9% absorption of learning at good category in experimental group while 63,2% at good enough category in other group. Thereby concluded that the application Discovery Learning model can improve students physic psychomotor skill in class X Seri Rama YLPI senior hihg school at Pekanbaru