Vertical Distribution of Hard Corals in Southern Siladen Island

This study was aimed at provide information on hard coral distribution in southern Siladen Island. The work was done using SCUBA gear Line Intercept Transect (LIT). Thirty m long-line transects were placed at the reef flat, 5 m depth, 10 m depth, 15 m depth, and 20 m depth. A total of 44 hard coral genera was recorded, and the highest number of genre was found at 5 m depth. Coral species diversity was also high enough at the reef flat (1.032) and 5 m depth (1.28). Coral reef condition at 10 m depth was good enough as well and categorized as productive due to much higher percent of the biotic component than the abiotic component. The dominant life forms consisted of tabulate Acropora and branching corals at the reef flat, encrusting corals, branching corals, and foliose corals at 5 m, encrusting corals at 10 and 20 m depth, and massive corals, encrusting corals, and branching corals at 15 m depth, respectively

Electrochemical Behavior of Chlorine on Platinum Microdisk and Screen-Printed Electrodes in a Room Temperature Ionic Liquid

As a result of the toxic and corrosive nature of chlorine gas, simple methods for its detection are required for monitoring and control purposes. In this paper, the electrochemical behavior of chlorine on platinum working electrodes in the room temperature ionic liquid (RTIL) 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][NTf2]) is reported, as a basis for simple sensor devices. Cyclic voltammetry (CV) and chronoamperometry (CA) on a Pt microelectrode revealed the two-electron reduction of Cl2 to chloride ions. On the CV reverse sweep, an oxidation peak due to the oxidation of chloride was observed. The reduction process was diffusion controlled at the concentrations studied (≤4.5% in the gas phase), in contrast to a previous report (J. Phys. Chem. C2008, 112, 19477), which examined only 100% chlorine. The diffusion-controlled currents were linear with gas-phase concentration. Fitting of the CA transients to the Shoup and Szabo expression gave a diffusion coefficient for chlorine in the RTIL of ca. 2.6 × 10–10 m2 s–1. Furthermore, determination of the equilibrium concentration of Cl2 in the RTIL phase as a function of gas-phase concentration enabled a value of 35 to be determined for the Henry’s law dimensionless volatility constant. The electrochemical behavior of chlorine on a Pt screen-printed electrode was also investigated, suggesting that these devices may be useful for chlorine detection in conjunction with suitable RTILs

Electrochemical Oxidation and Sensing of Methylamine Gas in Room Temperature Ionic Liquids

The electrochemical behaviour of methylamine gas in several room temperature ionic liquids (RTILs), [C2mim][NTf2], [C4mim][NTf2], [C6mim][FAP], [C4mpyrr][NTf2], [C4mim][BF4], and [C4mim][PF6] has been investigated on a Pt microelectrode using cyclic voltammetry. A broad oxidation wave at approximately 3 V, two reduction peaks and another oxidation peak was observed. A complicated mechanism is predicted based on the voltammetry obtained, with ammonia gas as a likely by-product. The currents obtained suggest that methylamine has a high solubility in RTILs, which is important for gas sensing applications. The analytical utility of methylamine was then studied in [C4mpyrr][NTf2] and [C2mim][NTf2]. A linear calibration graph with an R2 value of 0.99 and limits of detection of 33 and 34 ppm were obtained respectively, suggesting that RTILs are favourable non-volatile solvents for the electrochemical detection of highly toxic methylamine gas

Distribution and Diversity of Ascidian in Manado Bay, North Sulawesi

The purpose of this study was to determine the distribution and the diversity of ascidians in Manado Bay including species composition, density, diversity, and dominance. This study used the quadrat transect method. This study found differences in the number of ascidian species with water depth, 11 species of 5 families at 15 M depth, and 8 species of 3 families at 7 M depth. The diversity index ranged from 0.868 to 1.844 at 15 M depth and 0.965 to 1.864 at 7 M depth, the evenness index was 0.533 – 0.839 at 15 M depth and 0.600 – 0.897 at 7 M depth, the dominance index was 0.254 – 0.745 at 15 M depth and 0.254 – 0.708 at 7 M depth. Ascidian in Manado Bay had two distribution patterns, a uniform distribution pattern and a clustered distribution pattern. Environmental parameters had a water temperature of 27 oC – 31 oC, the salinity of 30 0/00 – 32 0/00, the brightness of 12 m – 14 m, and pH of 8 – 10.*Keywords: Ascidian; diversity; ecological index; distribution patternAbstrakTujuan dari penelitian ini adalah untuk mengetahui distribusi dan keanekaragaman jenis ascidia di perairan Teluk Manado meliputi: komposisi jenis, kepadatan individu, keanekaragaman, dan dominansi. Serta mengetahui pola distribusi ascidia. Penelitian ini menggunakan metode transek kuadran. Pada penelitian ini ditemukan perbedaan jumlah spesies ascidia menurut kedalaman, 11 spesies dari 5 family pada 15 M dan 8 spesies dari 3 famili pada kedalaman 7 m. Nilai indeks keanekaragaman ascidia di kedalaman 15 m = 0.868 – 1.844 dan 7 m = 0.965 - 1.864, indeks keseragaman 15 m = 0.533 – 0.839 dan 7 m = 0.600 – 0.897, indeks Dominasi15 m = 0.254 – 0.745 dan 7 m = 0.254 – 0.708. Ascdia di perairan Teluk Manado memiliki dua pola distribusi yaitu pola distribusi seragam dan pola distribusi mengelopok. Parameter lingkungan memiliki suhu air 27 oC – 31 oC, salinitas 30 0/00 – 32 0/00, kecerahan 12 m – 14 m, dan pH 8 – 10.*Kata kunci : Ascidia; keanekaragaman; indeks ekologi; pola distribus

Colloquium: The transport properties of graphene: An introduction

An introduction to the transport properties of graphene combining experimental results and theoretical analysis is presented. In the theoretical description simple intuitive models are used to illustrate important points on the transport properties of graphene. The concept of chirality, stemming from the massless Dirac nature of the low energy physics of the material, is shown to be instrumental in understanding its transport properties: the conductivity minimum, the electronic mobility, the effect of strain, the weak (anti-)localization, and the optical conductivity.Comment: As publishe

PENYULUHAN TEKNOLOGI BRIKET BIOARANG DARI SAMPAH ORGANIK BAGI KADER LINGKUNGAN

Abstrak: Diseminasi teknologi pembuatan briket bioarang dari sampah organik telah diberikan untuk warga dan kader lingkungan RW 03 Kelurahan Tambak Rejo, Kecamatan Simokerto, Kota Surabaya. Hal ini sangat penting mengingat wilayah RW 03 Kelurahan Tambak Rejo Surabaya, yang menjadi mitra kegiatan ini, merupakan daerah pemukiman padat penduduk dengan banyak tanaman perindang sehingga banyak dihasilkan sampah daun-daun tanaman. Selama ini, daun-daun tersebut hanya dibuang atau dibakar saja. Sementara itu, sebagian warga (mitra) belum memiliki pekerjaan tetap sehingga lebih daripada 50% warganya masuk dalam kategori masyarakat berpenghasilan rendah. Oleh karena itu, kegiatan ini ditujukan untuk membantu RW 03 Kelurahan Tambak Rejo, dalam hal ini sebagai mitra kegiatan, untuk menangani permasalahan sampah organik dan sekaligus memberikan peluang usaha/kerja dengan mengolah sampah organik tersebut menjadi produk energi alternatif yaitu briket bioarang. Untuk mencapai tujuan tersebut, tahapan kegiatan meliputi tahap persiapan, tahap pelaksanan pembuatan briket, dan tahap evaluasi kegiatan. Sistem evaluasi yang digunakan untuk mengukur kinerja kegiatan adalah dengan membagikan kuisioner kepada mitra. Indikator keberhasilan kegiatan ditunjukkan dengan minimal 70% mitra yang mengikuti kegiatan penyuluhan ini merasa puas dan merasakan manfaat kegiatan sehingga dapat membantu menyelesaikan masalah yang dihadapi mitra. Adapun yang menjadi mitra adalah 46 orang warga dan perangkat RW 03 Kelurahan Tambak Rejo Surabaya. Dari hasil kegiatan dapat disimpulkan bahwa mitra dapat memahami dan membuat briket dari sampah organik dengan baik. Parameter briket yang telah sesuai SNI adalah kadar air, kadar abu, kadar karbon, dan nilai kalor, sedangkan parameter volatile matter sedikit melebihi ketentuan SNI (7%). Hasil pengisian kuisioner yang dilakukan oleh mitra menunjukkan bahwa 100% peserta kegiatan puas dengan pelaksanaan kegiatan. Tidak hanya itu saja, kegiatan ini juga menjawab kebutuhan mereka sehinga tercipta peluang untuk menjadi sumber ekonomi baru.Abstract: Technology dissemination to prepare biocharcoal briquettes from organic waste has been carried out to residents and environmental cadres from RW 03 Tambak Rejo Village, Simokerto District, Surabaya City. The activity is urgent to be performed since the region is considered as the area with dense population with many plants and therefore, the kampong possesses a lot of leaves. So far, leaves waste is only thrown away or just burned. Meanwhile, some residents do not yet have permanent jobs and therefore, more than 50% of the residents are lied into society with low-income category. Accordingly, this activity was aimed to help society of RW 03 Tambak Rejo Village, in this context as our partners, to deal with leaves problem and in the same time provide business or work opportunity by processing those leaves into alternative energy product, namely briquette. To achieve these aims, several steps involve the preparation, the implementation and finally, the evaluation step have been carried out to assess the activity. The evaluation was performed by filling out questionnaires by partners who join in this activity, i.e. 46 people. In order to measure the success of this activity, we set that at least 70% of our partners feel satisfied that this activity will solve their problems. From the results it can be concluded that participants can understand theory behind organic wastes and briquettes, as well as able to make briquettes by theirselves. Several briquette parameters that comply with SNI are water content, ash content, carbon content and heating value, while the volatile matter parameters slightly exceed the SNI provisions (7%). Questionnaires filled out by mitra show that 100% of participants were satisfied with the implementation of this activity. In addition, the activity also answers their needs which in turn can create an opportunity to become a new economic source

Collective leadership dynamics among professional peers: Co-constructing an unstable equilibrium

Professional service firms (PSFs) are characterised by contingent and contested power relations among an extended group of professional peers. Studies of such firms can therefore yield important insights for the literatures on collective leadership and leader–follower relations. Yet to date PSF scholars have neglected the topic of leadership,and leadership scholars have neglected the context of PSFs.Based on 102 interviewsacross the consulting, accounting, and legal sectors, we identify three relational processesthrough which professional peers co-construct collective leadership:legitimising, negotiating, and manoeuvring. We demonstrate how the relational processes taken together constitute an unstable equilibrium, both in the moment and over time, emphasising how leadership in PSFs is inherently contested and fragile. Our model contributes to theories of collective leadership and leader–follower relations by foregrounding the power and politics thatunderlie collective leadership. We highlight the significance of the individual leader within the collective. We challengeassumptionsconcerning the binary nature of leadership and followership,by showing how colleagues may grant leadership identities to their peers without necessarily granting them leadership authority, and without claiming follower identities for themselves

The magnetic field of the B3V star 16 Pegasi

The Slowly Pulsating B3V star 16 Pegasi was discovered by Hubrig (2006) to be magnetic, based on low-resolution spectropolarimetric observations with FORS1 at the VLT. We have confirmed the presence of a magnetic field with new measurements with the spectropolarimeters Narval at TBL, France and Espadons at CFHT, Hawaii during 2007. The most likely period is about 1.44 d for the modulation of the field, but this could not be firmly established with the available data set. No variability has been found in the UV stellar wind lines. Although the star was reported once to show H alpha in emission, there exists at present no confirmation that the star is a Be star.Comment: 2 pages, 4 figures, contrubuted poster at IAU Symposium 259 "Cosmic Magnetic Fields: from Planets, to Stars and Galaxies", Tenerife, Spain, November 3-7, 200

Statistics of Magnetic Fields for OB Stars

Based on an analysis of the catalog of magnetic fields, we have investigated the statistical properties of the mean magnetic fields for OB stars. We show that the mean effective magnetic field ${\cal B}$ of a star can be used as a statistically significant characteristic of its magnetic field. No correlation has been found between the mean magnetic field strength ${\cal B}$ and projected rotational velocity of OB stars, which is consistent with the hypothesis about a fossil origin of the magnetic field. We have constructed the magnetic field distribution function for B stars, $F({\cal B})$, that has a power-law dependence on ${\cal B}$ with an exponent of $\approx -1.82$. We have found a sharp decrease in the function $F({\cal B})$F for {\cal B}\lem 400 G that may be related to rapid dissipation of weak stellar surface magnetic fields.Comment: 22 pages, 7 figures, accepted Astronomy Letters, 2010, vol.36, No.5, pp.370-379, contact E-mail: [email protected]

If the shoe fits : Development of an on-line tool to aid practitioner/patient discussions about 'healthy footwear'

Background: A previous study highlighted the importance of footwear to individuals' sense of their identity, demonstrating that shoes must 'fit' someone socially, as well as functionally. However, unhealthy shoes can have a detrimental effect on both foot health and mobility. This project utilises qualitative social science methods to enable podiatrists to understand the broader contribution of footwear to patients' sense of themselves and from this an online toolkit was developed to aid footwear education. Method: Semi-structured interviews were conducted with six podiatrists/shoe-fitters and 13 people with foot pathologies, some of whom also completed shoe diaries. These were supplemented with some follow-up interviews and photographs of participants' own shoes were taken to allow in-depth discussions. Results: Four areas related to 'fit' were identified; practicalities, personal, purpose and pressures, all of which need to be considered when discussing changes in footwear. These were incorporated into an online toolkit which was further validated by service users and practitioners in a focus group. Conclusion: This toolkit can support podiatrists in partnership with patients to identify and address possible barriers to changing footwear towards a more suitable shoe. Enabling patients to make healthier shoe choices will help contribute to improvements in their foot health and mobility