Solution-Processable Graphene Oxide as an Efficient Hole Injection Layer for High Luminance Organic Light-Emitting Diodes

The application of solution-processable graphene oxide (GO) as hole injection layer in organic light-emitting diodes (OLEDs) is demonstrated. High luminance of over 53,000 cd m-2 is obtained at only 10 V. The results will unlock a route of applying GO in flexible OLEDs and other electrode applications.Comment: 14 pages, 3 figures, 1 tabl

Pengaruh Kombinasi Media Pembelajaran terhadap Minat Belajar Mahasiswa pada Mata Kuliah Teknologi Pembelajaran Akuntansi

Tujuan penelitian ini adalah untuk mengetahui pengaruh kombinasi media pembelajaran (Microsoft PowerPoint dan Ulead Video Studio) terhadap minat belajar mahasiswa pada perkuliahan Teknologi Pembelajaran Akuntansi. Populasi yang digunakan dalam penelitian ini adalah mahasiswa semester IV Pendidikan Ekonomi BKK Pendidikan Akuntansi yang sedang mengikuti mata kuliah Teknologi Pembelajaran Akuntansi. Dalam penelitian ini, teknik pengambilan sampel yang dipilih adalah Nonprobability Sampling dengan Teknik Sampling Jenuh. Data yang digunakan adalah data primer yang berasal dari angket yang disebarkan oleh peneliti kepada mahasiswa sebagai responden pada akhir perkuliahan. Penelitian ini merupakan penelitian kuantitatif dengan menggunakan metode eksperimen, metode uji statistik yang digunakan adalah Uji-T dengan melakukan uji persyaratan analisis terlebih dahulu.Hasil penelitian menunjukkan bahwa terdapat pengaruh penggunaan kombinasi media pembelajaran terhadap minat belajar mahasiswa. Hal tersebut ditunjukkan melalui perhitungan Uji-T yang menghasilkan nilai t hitung sebesar 2,040 yang melebihi nilai t tabel sebesar 1,998 dan P-Value sebesar 0,045 lebih kecil dari taraf signifikansi yang telah ditentukan yaitu sebesar 0,05.Kata Kunci: Kombinasi Media Pembelajaran, Minat Belajar ABSTRACTThe purpose of this research is to know the effect of learning media combination (Microsoft PowerPoint and Ulead Video Studio) toward students interest in learning on Teknologi Pembelajaran Akuntansi course. The population that is used in this research is the 4th semester students of Economic Accounting Education who are joining Teknologi Pembelajaran Akuntansi course. In this research, sampling technique which choosen was Nonprobability Sampling withJenuh Sampling Technique. The determination of the group will be treated experimental and control is conducted randomly. The data that used is primary data which come from distributed questionnaries by researcher to students as respondents when the course ends. This research is quantitative research using experimental methods, statistical methods which used is T-Test with the test requirements prior analysis.The research result shows that learning media combination has effect to students interest in learning. It is shown by t0 = 2,040 which exceed the value of its critical value for 1,998 and P-Value for 0,045 smaller than a predetermined significance level for 0,05. Keyword: Learning Media Combination, Students Interest in LearningABSTRAKTujuan penelitian ini adalah untuk mengetahui pengaruh kombinasi media pembelajaran (Microsoft PowerPoint dan Ulead Video Studio) terhadap minat belajar mahasiswa pada perkuliahan Teknologi Pembelajaran Akuntansi. Populasi yang digunakan dalam penelitian ini adalah mahasiswa semester IV Pendidikan Ekonomi BKK Pendidikan Akuntansi yang sedang mengikuti mata kuliah Teknologi Pembelajaran Akuntansi. Dalam penelitian ini, teknik pengambilan sampel yang dipilih adalah Nonprobability Sampling dengan Teknik Sampling Jenuh. Data yang digunakan adalah data primer yang berasal dari angket yang disebarkan oleh peneliti kepada mahasiswa sebagai responden pada akhir perkuliahan. Penelitian ini merupakan penelitian kuantitatif dengan menggunakan metode eksperimen, metode uji statistik yang digunakan adalah Uji-T dengan melakukan uji persyaratan analisis terlebih dahulu.Hasil penelitian menunjukkan bahwa terdapat pengaruh penggunaan kombinasi media pembelajaran terhadap minat belajar mahasiswa. Hal tersebut ditunjukkan melalui perhitungan Uji-T yang menghasilkan nilai t hitung sebesar 2,040 yang melebihi nilai t tabel sebesar 1,998 dan P-Value sebesar 0,045 lebih kecil dari taraf signifikansi yang telah ditentukan yaitu sebesar 0,05.Kata Kunci: Kombinasi Media Pembelajaran, Minat Belajar ABSTRACTThe purpose of this research is to know the effect of learning media combination (Microsoft PowerPoint and Ulead Video Studio) toward students interest in learning on Teknologi Pembelajaran Akuntansi course. The population that is used in this research is the 4th semester students of Economic Accounting Education who are joining Teknologi Pembelajaran Akuntansi course. In this research, sampling technique which choosen was Nonprobability Sampling withJenuh Sampling Technique. The determination of the group will be treated experimental and control is conducted randomly. The data that used is primary data which come from distributed questionnaries by researcher to students as respondents when the course ends. This research is quantitative research using experimental methods, statistical methods which used is T-Test with the test requirements prior analysis.The research result shows that learning media combination has effect to students interest in learning. It is shown by t0 = 2,040 which exceed the value of its critical value for 1,998 and P-Value for 0,045 smaller than a predetermined significance level for 0,05

Empirically modelled Pc3 activity based on solar wind parameters

It is known that under certain solar wind (SW)/interplanetary magnetic field (IMF) conditions (e.g. high SW speed, low cone angle) the occurrence of ground-level Pc3–4 pulsations is more likely. In this paper we demonstrate that in the event of anomalously low SW particle density, Pc3 activity is extremely low regardless of otherwise favourable SW speed and cone angle. We re-investigate the SW control of Pc3 pulsation activity through a statistical analysis and two empirical models with emphasis on the influence of SW density on Pc3 activity. We utilise SW and IMF measurements from the OMNI project and ground-based magnetometer measurements from the MM100 array to relate SW and IMF measurements to the occurrence of Pc3 activity. Multiple linear regression and artificial neural network models are used in iterative processes in order to identify sets of SW-based input parameters, which optimally reproduce a set of Pc3 activity data. The inclusion of SW density in the parameter set significantly improves the models. Not only the density itself, but other density related parameters, such as the dynamic pressure of the SW, or the standoff distance of the magnetopause work equally well in the model. The disappearance of Pc3s during low-density events can have at least four reasons according to the existing upstream wave theory: 1. Pausing the ion-cyclotron resonance that generates the upstream ultra low frequency waves in the absence of protons, 2. Weakening of the bow shock that implies less efficient reflection, 3. The SW becomes sub-Alfvénic and hence it is not able to sweep back the waves propagating upstream with the Alfvén-speed, and 4. The increase of the standoff distance of the magnetopause (and of the bow shock). Although the models cannot account for the lack of Pc3s during intervals when the SW density is extremely low, the resulting sets of optimal model inputs support the generation of mid latitude Pc3 activity predominantly through upstream waves

Multidimensional Binary Vector Assignment problem: standard, structural and above guarantee parameterizations

In this article we focus on the parameterized complexity of the Multidimensional Binary Vector Assignment problem (called \BVA). An input of this problem is defined by $m$ disjoint sets $V^1, V^2, \dots, V^m$, each composed of $n$ binary vectors of size $p$. An output is a set of $n$ disjoint $m$-tuples of vectors, where each $m$-tuple is obtained by picking one vector from each set $V^i$. To each $m$-tuple we associate a $p$ dimensional vector by applying the bit-wise AND operation on the $m$ vectors of the tuple. The objective is to minimize the total number of zeros in these $n$ vectors. mBVA can be seen as a variant of multidimensional matching where hyperedges are implicitly locally encoded via labels attached to vertices, but was originally introduced in the context of integrated circuit manufacturing. We provide for this problem FPT algorithms and negative results ($ETH$-based results, $W$[2]-hardness and a kernel lower bound) according to several parameters: the standard parameter $k$ i.e. the total number of zeros), as well as two parameters above some guaranteed values.Comment: 16 pages, 6 figure

Empirically modelled Pc3 activity based on solar wind parameters

It is known that under certain solar wind (SW)/interplanetary magnetic field (IMF) conditions (e.g. high SW speed, low cone angle) the occurrence of ground-level Pc3–4 pulsations is more likely. In this paper we demonstrate that in the event of anomalously low SW particle density, Pc3 activity is extremely low regardless of otherwise favourable SW speed and cone angle. We re-investigate the SW control of Pc3 pulsation activity through a statistical analysis and two empirical models with emphasis on the influence of SW density on Pc3 activity. We utilise SW and IMF measurements from the OMNI project and ground-based magnetometer measurements from the MM100 array to relate SW and IMF measurements to the occurrence of Pc3 activity. Multiple linear regression and artificial neural network models are used in iterative processes in order to identify sets of SW-based input parameters, which optimally reproduce a set of Pc3 activity data. The inclusion of SW density in the parameter set significantly improves the models. Not only the density itself, but other density related parameters, such as the dynamic pressure of the SW, or the standoff distance of the magnetopause work equally well in the model. The disappearance of Pc3s during low-density events can have at least four reasons according to the existing upstream wave theory: 1. Pausing the ion-cyclotron resonance that generates the upstream ultra low frequency waves in the absence of protons, 2. Weakening of the bow shock that implies less efficient reflection, 3. The SW becomes sub-Alfvénic and hence it is not able to sweep back the waves propagating upstream with the Alfvén-speed, and 4. The increase of the standoff distance of the magnetopause (and of the bow shock). Although the models cannot account for the lack of Pc3s during intervals when the SW density is extremely low, the resulting sets of optimal model inputs support the generation of mid latitude Pc3 activity predominantly through upstream waves

The AMIGA sample of isolated galaxies. IV. A catalogue of neighbours around isolated galaxies

Studies of the effects of environment on galaxy properties and evolution require well defined control samples. Such isolated galaxy samples have up to now been small or poorly defined. The AMIGA project (Analysis of the interstellar Medium of Isolated GAlaxies) represents an attempt to define a statistically useful sample of the most isolated galaxies in the local (z < 0.05) Universe. A suitable large sample for the AMIGA project already exists, the Catalogue of Isolated Galaxies (CIG, Karachentseva 1973; 1050 galaxies), and we use this sample as a starting point to refine and perform a better quantification of its isolation properties. Digitised POSS-I E images were analysed out to a minimum projected radius R > 0.5 Mpc around 950 CIG galaxies (those within Vr = 1500 km s-1 were excluded). We identified all galaxy candidates in each field brighter than B = 17.5 with a high degree of confidence using the LMORPHO software. We generated a catalogue of approximately 54 000 potential neighbours (redshifts exist for 30% of this sample). Six hundred sixty-six galaxies pass and two hundred eighty-four fail the original CIG isolation criterion. The available redshift data confirm that our catalogue involves a largely background population rather than physically associated neighbours. We find that the exclusion of neighbours within a factor of four in size around each CIG galaxy, employed in the original isolation criterion, corresponds to Delta Vr ~ 18000 km s-1 indicating that it was a conservative limit. Galaxies in the CIG have been found to show different degrees of isolation. We conclude that a quantitative measure of this is mandatory. It will be the subject of future work based on the catalogue of neighbours obtained here.Comment: Accepted by A&A, 10 pages, 8 figures, 4 table

Estimated Risk of HIV Acquisition and Practice for Preventing Occupational Exposure: A Study of Healthcare Workers at Tumbi and Dodoma Hospitals, Tanzania.

Health care workers (HCWs) are at risk of acquiring human immuno-deficiency virus (HIV) and other infections via exposure to infectious patients' blood and body fluids. The main objective of this study was to estimate the risk of HIV transmission and examine the practices for preventing occupational exposures among HCWs at Tumbi and Dodoma Hospitals in Tanzania. This study was carried out in two hospitals, namely, Tumbi in Coast Region and Dodoma in Dodoma Region. In each facility, hospital records of occupational exposure to HIV infection and its management were reviewed. In addition, practices to prevent occupational exposure to HIV infection among HCWs were observed. The estimated risk of HIV transmission due to needle stick injuries was calculated to be 7 cases per 1,000,000 HCWs-years. Over half of the observed hospital departments did not have guidelines for prevention and management of occupational exposure to HIV infections and lacked well displayed health and safety instructions. Approximately, one-fifth of the hospital departments visited failed to adhere to the instructions pertaining to correlation between waste materials and the corresponding colour coded bag/container/safety box. Seventy four percent of the hospital departments observed did not display instructions for handling infectious materials. Inappropriate use of gloves, lack of health and safety instructions, and lack of use of eye protective glasses were more frequently observed at Dodoma Hospital than at Tumbi Hospital. The poor quality of the hospital records at the two hospitals hampered our effort to characterise the risk of HIV infection acquisition by HCWs. Greater data completeness in hospital records is needed to allow the determination of the actual risk of HIV transmission for HCWs. To further reduce the risk of HIV infection due to occupational exposure, hospitals should be equipped with sufficient personal protective equipment (PPE) and HCWs should be reminded of the importance of adhering to universal precautions

A critical appraisal of molecular xenomonitoring as a tool for assessing progress toward elimination of lymphatic filariasis

We used molecular xenomonitoring (MX, detection of filarial DNA in mosquitoes) to evaluate the impact of mass drug administration (MDA) in sentinel locations in Egypt with high (11.5%) and low (4.1%) baseline microfilaria prevalence rates. Blood-fed Culex pipiens were pooled by household and tested for Wuchereria bancrofti DNA by PCR. There was no significant relationship between the infection status of household residents and parasite DNA status of mosquitoes from the same houses. After 5 MDA rounds, parasite DNA rates in mosquitoes in high- and low-prevalence areas were reduced by 93.8% and 100% to 0.19% (95% CI: 0.076–0.382%) and 0% (95% CI: 0–0.045%), respectively. These changes were consistent with decreases in microfilaria prevalence rates in these sites; they provide insight regarding the minimal mosquito DNA rates necessary for sustained transmission of filariasis in Egypt. We conclude that MX is a powerful tool for monitoring the impact of MDA on filariasis endemicity and transmission