Kinetics of the ClO + HOreaction over the temperature range T = 210–298 K

The rate coefficient for the atmospherically important radical reaction: ClO + HO2 → Productswhich leads to ozone depletion, has been studied over the temperature range T = 210–298 K and at ambient pressure p = 760 ± 20 Torr. The reaction was studied using laser flash photolysis radical generation coupled with broadband charge coupled device absorption spectroscopy employing a two-dimensional charge-coupled-device (CCD) detection system. ClO radicals were generated following the photolysis of Cl2 and Cl2O gas mixtures diluted in nitrogen and oxygen. ClO radicals were monitored using broadband fingerprinting of their characteristic vibronic (A2Π ← X2Π) spectral structure, representing a definitive monitoring of this radical. Addition of hydroperoxy radical precursors to the gas mixture (methanol and oxygen) subsequently led to a competition for photolytically generated Cl atoms and a simultaneous prompt formation of both ClO and HO2 radicals. Detailed analysis and modelling of the radical production routes provided a degree of constraint into numerical integration simulations which were then used to interrogate and fit to ClO temporal profiles to extract the rate coefficient k1. The ambient temperature (T = 298 K) rate coefficient reported is k1 = (8.5 ± 1.5) × 10−12 cm3 molecule−1 s−1. The rate coefficient, k1, is described by the Arrhenius expression:where errors are 1σ statistical only. This significant rate coefficient is greater than previously reported, with a stronger negative temperature dependence than previously observed. Consequently this suggests that the contribution of reaction (1) to ozone loss, in particular at mid-latitudes might be currently underestimated in models. This work reports atmospheric pressure kinetic parameters for this reaction which are greater than those reported from low pressure studies, perhaps supporting ClO and HO2 association as predicted by previous theoretical studies of this process and highlighting the need for further pressure dependent experimental studies of the title reaction, which has been demonstrated here to be effective as an ozone loss process over a wide temperature range

Kinetics of the ClO + CH3O2 reaction over the temperature range T = 250 – 298 K

The kinetics of the potentially atmospherically important ClO + CH3O2 reaction (1) have been studied over the range T = 250–298 K at p = 760 Torr using laser flash photolysis radical generation, coupled with time resolved ultraviolet absorption spectroscopy, employing broad spectral monitoring using a charge coupled device detector array. ClO radicals were monitored unequivocally using this technique, and introduction of CH3O2 precursors ensured known initial methylperoxy radical concentrations. ClO temporal profiles were thereafter analysed to extract kinetic parameters for reaction (1). A detailed sensitivity analysis was also performed to examine any potential systematic variability in k1 as a function of kinetic or physical uncertainties. The kinetic data recorded in this work show good agreement with the most recent previous study of this reaction, reported by Leather et al. The current work reports an Arrhenius parameterisation for k1, given by: k(1)(T) = 2.2+3.4-1.3 x 10^-11 e(-(642+-253)K/T)cm^3 molecule^-1 s^-1. This work therefore concurs with that of Leather et al. implying that the title reaction is potentially less significant in the atmosphere than inferred from preceding studies. However, reaction (1) is evidently a non-terminating radical reaction, whose effects upon atmospheric composition therefore need to be ascertained through atmospheric model studies

The radius and entropy of a magnetized, rotating fully-convective star: analysis with depth-dependent mixing length theories

This is the author accepted manuscript. The final version is available from American Astronomical Society / IOP Publishing via the DOI in this record.Some low-mass stars appear to have larger radii than predicted by standard 1D structure models; prior work has suggested that inefficient convective heat transport, due to rotation and/or magnetism, may ultimately be responsible. We examine this issue using 1D stellar models constructed using Modules for Experiments in Stellar Astrophysics (MESA). First, we consider standard models that do not explicitly include rotational/magnetic effects, with convective inhibition modeled by decreasing a depth-independent mixing length theory (MLT) parameter αMLT (following Cox et al. 1981; Chabrier et al. 2007). We provide formulae linking changes in αMLT to changes in the interior specific entropy, and hence to the stellar radius. Next, we modify the MLT formulation in MESA to mimic explicitly the influence of rotation and magnetism, using formulations suggested by Stevenson (1979) and MacDonald & Mullan (2014) respectively. We find rapid rotation in these models has a negligible impact on stellar structure, primarily because a stars adiabat, and hence its radius, is predominantly affected by layers near the surface; convection is rapid and largely uninfluenced by rotation there. Magnetic fields, if they influenced convective transport in the manner described by MacDonald & Mullan (2014), could lead to more noticeable radius inflation. Finally, we show that these non-standard effects on stellar structure can be fabricated using a depth-dependent αMLT: a non-magnetic, non-rotating model can be produced that is virtually indistinguishable from one that explicitly parameterizes rotation and/or magnetism using the two formulations above. We provide formulae linking the radially-variable αMLT to these putative MLT reformulations

The changing role of the primary school teacher in Swaziland in the context of HIV/AIDS: teacher as caretaker and economic provider.

Swaziland has the world’s highest HIV prevalence with 26% of adults aged 15-49 years living with HIV. There are approximately 17,000 Swazi children aged 0 to 14 years living with HIV. This qualitative study explored the experiences of Swazi teachers supporting learners living with or affected by HIV/AIDS, with a specific focus on the extent to which teachers are aware of the “Rights of the Child” in their teaching and approaches. Important themes emerged from thematic analysis including the following: teachers provided more than education to learners living with and affected by HIV, including material goods and additional time, in some cases at the expense of other learners. In the era of HIV/AIDS, the teacher has become the emotional caretaker and economic provider in addition to the predictable role of educator in Swaziland. Education curricula in HIV-burdened countries need to modify training programmes and support services available to teachers to accommodate the complex role that teachers play in caring for learners living with and affected by HIV

Short-Term Rental Platform in the Urban Tourism Context: A Geographically Weighted Regression (GWR) and a Multiscale GWR (MGWR) Approaches

This article contributes to advancing the knowledge on the phenomenon of the most popular short-term rental platforms, Airbnb. By implementing a geographically weighted regression (GWR) and its multiscale form, MGWR, we examine the relationship between Airbnb locations and the core elements of urban tourism including hotels, food and beverages (F&B) venues, as well as access to public transport. This article’s contributions are twofold: methodological and empirical. First, the results show that incorporating localities improve overall model performance. It allows us to account for the nuance of each area of interest as the MGWR performs slightly better than the GWR in the case of spatially sparse data. Second, both models show that Airbnbs collocate with hotels supported by various amenities, but Airbnbs also go beyond traditional hotel zones. This analysis highlights and extends the latter where Airbnb concentrations are those for which there are strong associations with F&B establishments and access to public transports. This suggests that Airbnbs might benefit local businesses outside the reach of major tourist zones. However, there is further work to be done to understand whether the economic benefit to the local economy is worth the associated social costs raised by previous studies

STUDY CASE CONTROL PENGGUNAAN SMARTPHONE BERDASARKAN KARAKTERISTIK ANAK USIA 3-6 TAHUN DI TK. NUSA INDAH KECAMATAN PEUSANGAN KABUPATEN BIREUEN TAHUN 2019

Data Keminfo yang mengelompokkan komposisi usia, persentase pengguna smartphone yang termasuk kategori usia anak-anak  di Indonesia cukup tinggi, yaitu sekitar dari 36 % anak usia 3-10 tahun diproyeksikan menggunakan ponsel pintar pada tahun 2018. Lembaga riset Digital Marketing Emarketer memperkirakan pada 2018 jumlah pengguna aktif  smartphone di Indonesia lebih dari 100 juta orang. Penelitian ini bertujuan untuk mengetahui gambaran penggunaan smartphone berdasarkan karakteristik anak pada anak usia 3 – 6 tahun. Tehnik penelitian menggunakan metode observasi analitik dengan metode case control study  digunakan sebagai panduan arah pengumpulan data  dari total 96 responden dengan menggunakan perbandingan 1:2 dibagi menjadi 32 responden sebagai pengguna smartphone dan 64 responden yang tidak menggunakan smartphone, penentuan kasus penggunaan smartphone berdasarkan sesuai dengan kriteria penelitian. Penelitian dilakukan di TK Nusa Indah Kecamatan Peusangan Kabupaten Bireuen  pada tanggal 21 November 2018 s/d 30 April 2019. Pengumpulan data ini menggunakan kuesioner. Dari hasil penelitaian dididapatkan proporsi responden mayoritas adalah berjenis kelamin perempuan baik dari kelompok kasus 16 (50%) maupun kelompok Kontrol 34 (53%). Dari segi umur responden diketahui persentasi dari 32 kasus dari 64 kontrol responden mayoritas dengan umur 5 - ≤ 6 tahun 78 (81%).  Dari segi status kedudukan anak dari 96  responden diketahui persentasi dari 32 kasus dan 64 kontrol proporsi dengan status kedudukan anak mayoritas  anak lahir dengan urutan anak ke 1 (pertama) baik dari kelompok kasus 18 (56%). Sebaiknya tidak diberikan smartphone kepada anak usia 3-6 tahun, seharusnya mereka bermain dengan teman-teman sebayanya. Alangkah  lebih baik jika anak-anak bermain permainan tradisional atau sekedar mengobrol bercerita dengan teman-teman mereka. Kata Kunci: Smartphone, Ana

Kinetic studies of the atmospherically implicated halogen oxide radical and peroxy radical cross-reactions

The occurrence of halogen oxide radicals, XO (X = Cl, Br, I), which are formed by the reaction of photolytically released halogen atoms with ozone, has a profound impact on atmospheric chemistry. XO radicals not only react with themselves but they are also believed to react in the atmosphere with other key radical species. In particular, XO can react with peroxy radicals, RO2, which are key members of the so called “odd hydrogen” radical family, HOx. Detailed laboratory studies of the kinetics of reactions of the type XO + RO2 → Products are therefore important in assessing their atmospheric importance and understanding the atmospheric implications of such chemistry. The kinetics of several XO + RO2 (X = Cl or Br and R = H or CH3) reactions have been studied as a function of temperature (T = 210 – 314 K) at p = 760 ± 20 Torr, using the laser flash photolysis technique coupled with UV absorption spectroscopy employing a charge coupled device (CCD) detection system for radical monitoring. Application of CCD detection facilitated the real time monitoring of the XO radical species concentration in each reaction studied. This was afforded by the rapid acquisition of broadband sequential spectra by the CCD where transmitted light intensities were converted into absorbances by Beer’s law. Exploiting the vibronic structure characteristic to XO radicals via ‘differential’ spectroscopy, unequivocal monitoring of XO was afforded by converting the resultant differential absorbances into concentrations using the Beer-Lambert law. The obtained temporal XO concentration profiles were then analysed using detailed numerical models. Strict control of successive experimental conditions and constraints in each fitting model used allowed the initial concentrations of RO2 to be inferred and their temporal behaviour simulated alongside the measured temporal XO profiles to obtain kinetic information on each reaction investigated

Perilaku Bidan Kia/kb dalam Pelaksanaan Program Prevention Of Mother To Child Transmission (Pmtct) di Rumah Sakit Haji Kota Medan Tahun 2013

The spread of HIV/AIDS in Indonesia is very fast . Currently there is no province in Indonesia that is free of HIV. PMTCT is an effort to prevent HIV transmission from mother to baby and an effective strategy to cover a broad spectrum, not only the housewives, but also to prostitute, female using injecting drug, migrant workers and others. In Medan there are two hospitals that serve governments PMTCT program. On observations found only 1 midwife who trained in PMTCT programs . The purpose of this study is to describe the behavior of midwives in the implementation of the PMTCT program (Prevention of Mother to Child Transmission) at Haji Hospital in Medan at 2013. This is a descriptive study with a qualitative approach using in-depth interviews to determine the behavior of midwives in the implementation of PMTCT (Prevention of Mother to Child Transmission) at Haji Hospital in Medan at 2013. Results showed midwives knowledge are still low about PMTCT (Prevention of Mother To Child Transmission) program. Midwives attitude positive outlook where midwives do not discriminate patients. Action of midwives in the face of patients didn't match with the guidebook of PMTCT program. For thatis expected to the hospital to evaluatiate, train, and sosialize the PMTCT program, which is management of HIV infection and antiretroviral therapy for children, adolescent and adults, to assisting patient of PMTCT, and support to patient of PMTCT. Midwives is also espected to read and seek for more information about PMTCT

Analisis Spasial Kejadian Tuberkulosis di Kabupaten Sukoharjo Tahun 2012

Tuberkulosis sebagai penyakit menular masih menjadi masalah kesehatan di Indonesia. Kasus tuberkulosis di Kabupaten Sukoharjo dari tahun 2010 sampai dengan 2012, cenderung mengalami kenaikan. Tujuan penelitian ini untuk menganalisis spasial kejadian tuberkulosis di Kabupaten Sukoharjo. Penelitian ini merupakan penelitian deskriptif dengan analisis spasial yang mengambil titik koordinat tempat tinggal penderita tuberkulosis BTA (+) dengan menggunakan alat bantu GPS (Global Positioning System). Jumlah sampel yang digunakan 105, dengan metode stratifikasi proporsional. Hasil penelitian ini menunjukkan persebaran kejadian tuberkulosis menyebar di 12 Puskesmas Kabupaten Sukoharjo dengan kasus tertinggi di Puskesmas Nguter sejumlah 17 penderita (16,2%) dan kasus terendah di Puskemas Gatak sejumlah 4 penderita (3,8%). Distrubusi kejadian tuberkulosis berdasarkan lingkungan rumah: lantai rumah kedap air sejumlah 59 penderita (56,2%) dan tidak kedap air sejumlah 46 penderita (43,8%), ventilasi yang memenuhi syarat sebanyak 35 penderita (33,3%) dan tidak memenuhi syarat sebanyak 70 penderita (66,7%), kepadatan hunian rumah memenuhi syarat 100 penderita (92,5%), tidak memenuhi syarat 5 penderita (4,8%). Buffer Puskesmas dengan penderita tuberkulosis, jarak sangat jauh sebanyak 43 penderita (40,95%), jarak jauh sebanyak 45 penderita (42,86%), dan jarak dekat sebanyak 17 penderita (16,19%

Persepsi Jajaran Pimpinan Tentang Kawasan tanpa Rokok ( Ktr ) di Dinas Kesehatan Kabupaten Langkat Tahun 2014

No Smoking Area is a place or area that prohibited for production, sales, advertising, promotion and use of cigarettes activities. Determination of No Smoking Area is an effort to protect the public against the risk of health problems due to the threat of contaminated environment. This is background of researcher to conduct the research with using a qualitative studies to identify and understand the perception of the leadership ranks at the District Health Office Langkat about No Smoking Area year 2014 because the leadership is the people who are influential in establish a policy to be determined.This study uses a qualitative approach that utilizes a data collection technique with in-depth interviews to six-person as informant.The results showed all informants are agreeing on the No Smoking Area in District Health Office Langkat because it has a positive impact especially in health sector. Informants also had a strong commitment to realize it. The policy draft regarding to No Smoking Area expressed by several informants in written rules and sanctions, it starts with the appeal and the to awareness by using the health promotion steps. Therefore, researcher suggest that the Leadership ranks to sets the No Smoking Area immediately and dissemination of guidelines for implementation of the No Smoking Area.Keyword = perception, leadrship ranks, smoke and no smoking area