Dampak Teori Domino di Negara-Negara Afrika Utara

Penelitian ini bertujuan untuk mengungkap keterkaitan revolusi di negara-negara Afrika Utara, terutama yang terjadi di Mesir dan Libya yang notabene mayoritas penduduknya memeluk agama Islam. Penelitian ini menggunakan metode historis kritis, kritis meliputi 5 tahap, yaitu: (1) pemilihan topik, (2) heuristik, (3) verifikasi (keabsahan sumber, kritik sejarah), (4) interpretasi: analisis dan sintetis, dan (5) historiografi. Hasil dari penelitian ini menunjukkan bahwa terdapat kemiripan penyebab revolusi yang terjadi di negara-negara Afrika Utara, meliputi Mesir dan Libya. Kemiripan tersebut terletak pada dinamika pemerintahan yang sama-sama dipimpin oleh pemimpin yang telah lama berkuasa, sistem diktator, dan rendahnya tingkat kesejahteraan sosial, serta minimnya demokrasi. Hal ini sejalan dengan teori domino yang menjelaskan bahwa peristiwa yang terjadi di suatu negara bisa berdampak pada negara sekitar yang memiliki karakteristik yang sam

Wireless communication with mobile inspection robots while submerged inside oil storage tanks

Data acquisition during storage tank inspection is one of the most important aspects for petrochemical storage tank owners. Mobile inspection robots designed to enter inside a storage tank without taking the tank out of service are required to enter through manholes on the roof of the tank with openings as small as 300-millimetre diameter. These robots are controlled via an umbilical cable which supplies power to the robot, sends and receives signals to control robot motion, and transfers inspection data acquired by non-destructive testing (NDT) sensors back to NDT inspectors. It is important to localize a robot inside the tank so that NDT data indicating a defect such as corrosion pitting in tank floors or weld cracks can be mapped for subsequent monitoring and repair. Wireless communication with the robot for NDT data acquisition and localization would enable the minimization of umbilical size and its effective management which is important when a small mobile robot is supplied with a very long umbilical. This paper presents results of a study to develop a wireless communication system that uses radio frequency (RF) signals with low power (<1W) sent by a transceiver on a robot operating inside an oil storage tank which travel through an oil medium, are transmitted through steel tank walls and are captured by receivers placed in air outside the tank. Simulations using Feko software have been performed to assess the feasibility of using RF for communication in oil storage tanks with laboratory experiments conducted using vegetable oil to validate the simulations. RF signals transmitted by a robot operating inside an oil tank and received by a number of receivers placed in air around the tank has potential application as a robot localization system

Incidence and Predictors of Tuberculosis Among Adult PLWHA at Public Health Facilities of Hawassa City

Tuberculosis (TB) is the most frequently diagnosed opportunistic infection (OI) and disease in people living with HIV/AIDS (PLWHA), world-wide. This study aimed at determining the incidence and predictors of tuberculosis among people living with HIV.A Six year retrospective follow up study was conducted among adult PLHIV. The Cox proportional hazards model was used to identify predictors.A total of 554 patients were followed and produced 1830.3 person year of observation. One hundred sixty one new TB cases occurred during the follow up period. The overall incidence density of TB was 8.79 per 100 person-year (PY). It was high (148.71/100 PY) in the first year of enrolment. The cumulative proportion of TB free survival was 79% and 67% at the end of first and sixth years, respectively. Not having formal education(AHR=2.68, 95%CI: 1.41, 5.11 ), base line WHO clinical stage IV (AHR = 3.22, 95% CI=1.91-5.41), CD4 count &lt;50 cell/ul (AHR=2.41, 95%CI=1.31, 4.42), Being bed redden (AHR= 2.89, 95%CI=1.72, 3.78), past TB history (AHR=1.65, 95% CI = 1.06,2.39), substance use (AHR=1.46, 95% CI=1.03,2.06) and being on pre ART (AHR=1.62, 95%CI:1.03-2.54 ) were independently predicted tuberculosis occurrence. Advanced WHO clinical stage, limited functional status, past TB history, addiction and low CD4 (&lt;50cell/ul) count at enrollment were found to be the independent predictor of tuberculosis occurrence. Therefore early initiation of treatment and intensive follow up is important

Facile synthesis of mesoporous N doped zirconium titanium mixed oxide nanomaterial with enhanced photocatalytic activity under visible light

The present paper deals with a hydrazine mediated synthesis of high surface area and thermally stable N-doped zirconium titanium mixed oxide with enhanced photocatalytic activity towards reduction of selenium (VI) to metallic Se0 under visible light. Materials were synthesized at pH ¼ 2 by varying the hydrazine concentration and characterized by XRD, TEM, BET method, XPS, Raman spectroscopy and UV-vis solid state spectra. Presence of low amount of zirconium oxide (10 wt%) helps in phase stabilization and maintains the porous structure even at higher calcinations temperature in comparison to that of pure titania. XPS spectrum justifies the presence of nitrogen and Ti3+ in the material due to the decomposition reaction of hydrazine. Hydrazine controls the nitrogen content, surface area and the formation of oxygen vacancy in the material. Investigation of metal oxide to hydrazine ratio on the overall surface properties and photocatalytic activity indicates that the 1 : 6 ratio is the optimum composition for the best result. Surface area and pore volume increases to 298 m2/g and 0.323 cm3/g. The obtained material (TiZr-6N-400) is found to reduce selenium (VI) to selenium (0) under visible light within only 45 min of reaction. Increased photocatalytic activity under visible light is mostly due to the synergistic effect of substantial nitrogen doping, high surface area and presence of oxygen vacancy

Ultralong-Range Rydberg Molecules in a Divalent-Atomic System

We report the creation of ultralong-range Sr$_2$ molecules comprising one ground-state $5s^2$ $^1S_0$ atom and one atom in a $5sns$ $^3S_1$ Rydberg state for $n$ ranging from 29 to 36. Molecules are created in a trapped ultracold atomic gas using two-photon excitation near resonant with the $5s5p$ $^3P_1$ intermediate state, and their formation is detected through ground-state atom loss from the trap. The observed molecular binding energies are fit with the aid of first-order perturbation theory that utilizes a Fermi pseudopotential with effective $s$-wave and $p$-wave scattering lengths to describe the interaction between an excited Rydberg electron and a ground-state Sr atom.Comment: 5 pages, 2 figure

Photocatalytic Removal of Copper and Selenium from Waste water under Visible Light

Zirconia and silica mixed titanium oxides were synthe-sized by modified sol-gel method in presence of a surf-actant (CETAB). Materials were characterized by surface area, XRD, SEM and UV-Vis spectroscopy. Materials are found to be in uniform size and mostly spherical when synthesized in presence of CETAB. Effect of sum factant concentration on the particle size, shape and the catalytic activity is also evaluated. Calcination temp-erature plays an important role on the phase stability and catalytic activity of the materials. It is well observed that without any hole scavenger the efficiency of photocatalytic metal removal is quite low for both the metal ions within 30minuites of reaction. However, addition of hole scavenger increases the activity many folds and hence complete removal of Se and Cu was possible in 30 minutes of reaction. Among all the organic hole scavengers used, sodium formate is found to be the most active one for selenium whereas for copper EDTA is the most suitable one. Reaction pH also plays important role in the efficiency of the metal removal. Above all synth-esized materials are found to be efficient catalyst for visible light reaction. The same catalyst is found to be reusable at least for 5-6 times with 4-5% decrease in the activity