Pembuatan Karbon Aktif dari Kulit Durian sebagai Adsorbent Logam Fe

Durian peel is known as the waste that can pollute the environment. One effort to improve the economic value of the durian skin can be done with the process into activated carbon. This study aims to obtain optimum conditions for the use of activators of Kaliaum Hidroksida on the quality of activated carbon and activated carbon absorption of Fe metal. Activated carbon is made via two processes, namely the process of carbonization and activation at 320oC temperature with a solution of Kalium Hidroksida by varying the massa aktif carbon1, 1.5, 2, 2.5, dan 3 gr and adsorb time30, 60, 90, dan 120 menit. To determine the quality of activated carbon, activated carbon characteristics tested, such as moisture content, ash content, and the absorption of iodine. The results showed that the characteristics of activated charcoal SNI 06-3730-1995 meets the standards the water content of 14.12%, 5.46% ash content and absorption of I2 solution of 580.27 mg / g in adsorbing metals Fe. Application of Fe metal adsorption by activated carbon from durian skin with 3 grams of carbon mass variation and contact time of 90 minutes where the adsorption efficiency is 96.75%

Aplikasi Running Text Berupa Jadwal Sholat 5 Waktu pada Musholla Polman Negeri Bangka Belitung

Dalam agama Islam, sholat merupakan kewajiban yang harus dikerjakan oleh setiap pemeluknya yang sudah memenuhi syarat. Dalam satu hari satu malam terdapat lima waktu sholat, yaitu Isya, Subuh, Zuhur, Ashar, dan Maghrib. Salah satu amalan yang paling besar pahalanya adalah sholat berjamaah di masjid atau musholla pada saat sudah masuk waktu sholat. Biasanya beberapa masjid atau musholla sudah memiliki penanda datangnya waktu sholat yang dibuat secara otomatis, sehingga memudahkan muadzin untuk menyerukan adzan. Namun itu masih sebagian kecil saja. Masih banyak masjid atau musholla yang belum memiliki sarana penanda waktu sholat otomatis ini. Untuk itu mengetahui waktu shalat 5 waktu sangatlah penting bagi setiap pemeluk agama islam agar dapat menjalankan shalat 5 waktu tersebut dengan tepat dan sebaik-baiknya. Oleh karena itu penanda jadwal shalat itu sangat penting adanya. Maka sekarang ini banyak di masjid maupun di rumah-rumah yang biasanya sudah terdapat kalender maupun penampil waktu sholat abadi, akan tetapi tampilannya sangat kecil sehingga tidak dapat dilihat dari jarak jauh. Berdasarkan dari pengalaman itu dan pentingnya hal ini maka penulis membuat penampil waktu sholat yang dapat secara real time berubah mengikuti Perubahan hari, dan dapat dilihat dari jarak yang cukup jauh. Sehingga dapat lebih berfungsi optimal serta dapat memaksimalkan waktu yang ada

Conceptual Design of Unmanned Piston-Propeller Cargo Aircraft

The need for a transportation system to transport goods is increasing, especially for regions in Indonesia that are included in the leading, remote, and disadvantaged (3T) categories. This paper will discuss the conceptual design of an unmanned cargo aircraft with a piston-propeller engine which can later be operated in the 3T area. The design will begin with a discussion of DRO, followed by a concept of the aircraft configuration. After the configuration is formed, the aerodynamic characteristics will be calculated, the weight will be predicted, and flight performance calculations and aircraft stability will be calculate

Inducing Panchromatic Absorption and Photoconductivity in Polycrystalline Molecular 1D Lead-Iodide Perovskites through π-Stacked Viologens

As a consequence of their quantum- and electronically-confined inorganic lattices, molecular 1D lead-iodide perovskites are ill suited to photovoltaic (PV) applications. In order to circumvent these problems, we utilized electron accepting viologen (N,N'-dialkyl-4,4'-bipyridinium) dications incorporating hydrogen bond donor functionalities, which served to induce π-π stacking interactions. The resulting 'viologen dimers' display enhanced charge-transfer (CT) interactions with the 1D lead-iodide nanowires. This manifests in extended light absorption (up to 800 nm), reduced band gaps (1.74 eV to 1.77 eV), and longer photoluminescence lifetimes. More importantly, we demonstrate significant photoconductivity behavior in polycrystalline molecular 1D lead-iodide perovskites for the first time. Thus, this work offers a strategy for inducing the properties required for PV applications in molecular 1D lead-iodide perovskites. © 2018 American Chemical Society

Metal Coordination Sphere Deformation Induced Highly Stokes-Shifted, Ultra Broadband Emission in 2D Hybrid Lead-Bromide Perovskites and Investigation of Its Origin

Published studies of layered (2D) (100)-oriented hybrid lead-bromide perovskites evidence a correlation between increased inter-octahedral (Pb-Br-Pb) distortions and the appearance of broadband white light emission. However, the impact of distortions within their constituent [PbBr6]4- octahedra has yet to be assessed. Herein, we report two new (100)-oriented 2D Pb-Br perovskites, whose structures display unusually high intra-octahedral distortions, whilst retaining minimal inter-octahedral distortions. Using a combination of temperature-dependent, power-dependent and time-resolved photoluminescence spectroscopic measurements, we show that increased intra-octahedral distortion induces exciton localization processes and leads to formation of multiple photoinduced emissive colour centres. Ultimately, this leads to highly Stokes-shifted, ultrabroad white light emission at room temperature

Formation of Corrugated n = 1 2D Tin Iodide Perovskites and Their Use as Lead-Free Solar Absorbers

Major strides have been made in the development of materials and devices based around low-dimensional hybrid group 14 metal halide perovskites. Thus far, this work has mostly focused upon compounds containing highly toxic Pb, with the analogous less toxic Sn materials being comparatively poorly evolved. In response, the study herein aims to (i) provide insight into the impact of templating cation upon the structure of n = 1 2D tin iodide perovskites (where n refers to the number of contiguous two-dimensional (2D) inorganic layers, i.e., not separated by organic cations), and (ii) examine their potential as light absorbers for photovoltaic (PV) cells. It was discovered through systematic tuning of organic dications, that imidazolium rings are able to induce formation of (110)-oriented materials, including the examples of “3 × 3” corrugated Sn-I perovskites. This structural outcome is a consequence of a combination of supramolecular interactions of the two endocyclic N-atoms in the imidazolium functionalities with the Sn-I framework and the higher tendency of Sn2+ ions to stereochemically express their 5s2 lone pairs relative to the 6s2 electrons of Pb2+. More importantly, the resulting materials feature very short separations between their 2D inorganic layers with iodide–iodide (I···I) contacts as small as 4.174 Å, which is amongst the shortest ever recorded for 2D tin iodide perovskites. The proximate inorganic distances, combined with the polarizable nature of the imidazolium moiety, eases the separation of photogenerated charge within the materials. This is evident from the excitonic activation energies as low as 83(10) meV, measured for ImEA[SnI4]. When combined with superior light absorption capabilities relative to their lead congeners, this allowed fabrication of lead-free solar cells with incident photon-to-current and power conversion efficiencies of up to 70 % and 2.26 %, respectively, which are amongst the highest values reported for pure n = 1 2D group 14 metal halide perovskites. In fact, these values are superior to the corresponding lead iodide material, which demonstrates that 2D Sn-based materials have significant potential as less toxic alternatives to their Pb counterparts

Analisis Strategi Bandar Udara Notohadinegoro Dalam Meningkatkan Minat Pengguna Jasa Di Era Pandemi Covid-19

AbstrakDunia penerbangan di Indonesia mengalami dampak pandemi covid-19, pandemi ini menyebabkan maskapai penerbangan dan banyak pengelola bandara di Indonesia merugi. Hal tersebut membuat bandara Notohadinegoro menutup sementara aktivitas penerbangan hingga tidak melayani angkutan penumpang, sesuai dengan arahan pemerintah pusat. Tujuan dalam penelitian ini adalah untuk mengetahui bagaimana strategi serta hal-hal apa saja yang menghambat Bandara Notohadinegoro dalam upaya meningkatkan minat pengguna jasa di era pandemi Covid-19. Penelitian ini menggunakan metode penelitian deskriptif kualitatif dengan teknik pengumpulan data berupa observasi, wawancara dan dokumentasi. Strategi promosi Bandara Notohadinegoro adalah menggelar Joyflight yang bertujuan untuk menarik pengguna jasa kembali menikmati layanan penerbangan. Joy Flight bertujuan untuk meningkatkan pariwisata dengan melakukan perjalanan melalui kota Jember di udara, sehingga Bandar Udara Notohadinegoro tetap menunjukkan bahwa bandara tersebut tetap eksis meski tidak berfungsi secara normal. Beberapa hal yang menghambat proses perencanaan strategis bandar udara menarik minat pengguna jasa adalah terbatasnya sumber daya yang dibutuhkan pengelola bandar udara dan persaingan jasa transportasi yang lebih ekonomis. Bagi pihak bandara Notohadinegoro Jember sebaiknya terus berdiskusi dengan stakeholder, tidak hanya mengandalkan penumpang, tetapi dapat bekerjasama dengan pihak-pihak yang bersangkutan. Hal itu dapat dilakukan sebagai usaha untuk menarik maskapai agar kembali bekerja sama dengan bandar udara Notohadinegoro.Kata Kunci: Pandemi covid-19, Aktivitas penerbangan, Atrategi, Minat pengguna jasa AbstractThe world of aviation in Indonesia is experiencing the impact of the covid-19 pandemic, this pandemic has caused airlines and many airport managers in Indonesia to lose money. This has caused Notohadinegoro airport to temporarily close flight activities so that it does not serve passenger transportation, in accordance with the direction of the central government. The purpose of this study is to find out what strategies and things are hindering Notohadinegoro Airport in an effort to increase the interest of service users in the era of the Covid-19 pandemic. This study uses a qualitative descriptive research method with data collection techniques in the form of observation, interviews and documentation. Notohadinegoro Airport's promotional strategy is to hold Joyflight which aims to attract service users to enjoy flight services again. Joy Flight aims to increase tourism by traveling through the city of Jember in the air, so that Notohadinegoro Airport still shows that the airport still exists even though it is not functioning normally. Several things that hinder the airport's strategic planning process to attract service users are the limited resources needed by airport managers and competition for more economical transportation services. For Notohadinegoro Airport, Jember, it must continue to discuss with stakeholders, not only relying on passengers, but can work together with related parties. This can be done as an effort to attract airlines to cooperate with Notohadinegoro airport.Keyword: Covid-19 pandemic, Aviation activities, Strategies, Interests of service user

Direct Band Gap Mixed-Valence Organic-inorganic Gold Perovskite as Visible Light Absorbers

Lead-free halide perovskite semiconductors are necessary due to the atmospheric instability and lead toxicity associated with the 3D lead halide perovskites. However, a stable lead-free perovskite with an ideal band gap (1.2-1.4 eV) for photovoltaics is still missing. In this work, we synthesized organic-inorganic gold halide double perovskites ((CH3NH3)2[Au2X6], X = Br, I) through a solution-processed route that offers an ideal direct band gap for photovoltaic applications. Density functional theory calculations confirm the direct nature of the band gap with reasonable absorption coefficients in the visible range and excellent charge transport properties. In addition, the Au-halide perovskites show high chemical stability and photoresponse. These combined properties demonstrate that Au-based halide perovskites can be a promising group of compounds for optoelectronic applications