Rancangan Sensor Kecepatan Angin pada Wind Tunnel

Wind Tunnel is a tool used in aerodynamic research to study the effect of moving air trough solid object. Data retrieval carried out in the wind tunnel at Suryadarma still uses a ruler. The method is still manual, resulting in less precision in data collection.To facilitate reading in the wind tunnel, a system is made using the MPXV 7002 sensor. This data reading system is connected to an LCD as a display in monitoring the resulting speed changes.From the results of the study it can be concluded that the measurement of pressure the greater the rotation of the engine in the wind tunnel, the greater the value of pressure produced based on testing using MPXV7002 sensor with 800 RPM, 1000 RPM, 1200 RPM. The resulting voltage is 2.25 V, 2.27 V, 2.28 V. With observed speeds 8, 10, 12 m / s compared with anemometers 7.8 m / s, 9.5 m / s and 12 m / s. And the resulting error is 1.5%, 1.9%, 2%. Wind Tunnel adalah sebuah alat yang di gunakan dalam penelitian aerodinamika untuk mempelajari efek dari udara yang bergerak melewati benda padat. Pengambilan data yang dilakukan pada wind tunnel Universitas Suryadarma masih menggunakan penggaris. Cara tersebut masih manual sehingga mengakibatkan kurang presisi dalam pengambilan data. Untuk memudahkan pembacaan pada wind tunnel maka dibuatlah sebuah sistem dengan menggunakan sensor MPXV 7002. Sistem pembacaan data ini dihubungkan dengan sebuah LCD sebagai tampilan dalam memonitoring Perubahan kecepatan yang dihasilkan.Dari hasil penelitian dapat disimpulkan bahwa pengukuran tekanan semakin besar putaran Engine pada wind tunnel semakin besar pula nilai tekanan yang dihasilkan berdasarkan pengujian menggunakan sensor MPXV7002 dengan RPM 800, RPM 1000, RPM 1200 . Tegangan yang dihasilkan 2,25 V, 2,27 V, 2,28 V. Dengan kecepatan yang diamati 8, 10, 12 m/s dibandingkan dengan anemometer 7,8 m/s , 9,5 m/s dan 12 m/s. Dan eror yang dihasilkan 1,5 %, 1,9 %, 2 %

Aplikasi Accelerometer 3 Axis untuk Mengukur Sudut Kemiringan (Tilt) Engineering Model Satelit di Atas Air Bearing

This paper described of design of accelerometer application to measurement of tilt of engineering model of satellite. One of test satellite is how to control the satellite attitude, how to reduce the disturb. The satellite placed on the air bearing where it can free move like on the outer space. The satellite give a disturb until the attitude is change, where one of attitude is change is tilt. From the tilt the user can analyses and gave a command what to do. We use accelerometer type LIS3L06AL to sense a tilt. This sensor has sensitivity 0.66 V/g. The accelerometer placed on the air bearing where one of axis across with the earth. This condition, the accelerometer will force 1 g. If the accelerometer position is change, the accelerometer will act force 1 g times sin θ

Room temperature ferromagnetic-like behavior in Mn-implanted and post-annealed InAs layers deposited by Molecular Beam Epitaxy

We report on the magnetic and structural properties of Ar and Mn implanted InAs epitaxial films grown on GaAs (100) by Molecular Beam Epitaxy (MBE) and the effect of Rapid Thermal Annealing (RTA) for 30 seconds at 750C. Channeling Particle Induced X- ray Emission (PIXE) experiments reveal that after Mn implantation almost all Mn atoms are subsbtitutional in the In-site of the InAs lattice, like in a diluted magnetic semiconductor (DMS). All of these samples show diamagnetic behavior. But, after RTA treatment the Mn-InAs films exhibit room-temperature magnetism. According to PIXE measurements the Mn atoms are no longer substitutional. When the same set of experiments were performed with As as implantation ion all of the layers present diamagnetism without exception. This indicates that the appearance of room-temperature ferromagnetic-like behavior in the Mn-InAs-RTA layer is not related to lattice disorder produce during implantation, but to a Mn reaction produced after a short thermal treatment. X-ray diffraction patterns (XRD) and Rutherford Back Scattering (RBS) measurements evidence the segregation of an oxygen deficient-MnO2 phase (nominally MnO1.94) in the Mn-InAs-RTA epitaxial layers which might be on the origin of room temperature ferromagnetic-like response observed.Comment: 16 pages, 5 figures. Acepted in J. Appl. Phy

Stress- and phospholipid signalling responses in Arabidopsis PLC4-KO and -overexpression lines under salt- and osmotic stress

Several drought and salt tolerant phenotypes have been reported when overexpressing (OE) phospholipase C (PLC) genes across plant species. In contrast, a negative role for Arabidopsis PLC4 in salinity stress was recently proposed, showing that roots of PLC4-OE seedlings were more sensitive to NaCl while plc4 knock-out (KO) mutants were more tolerant. To investigate this apparent contradiction, and to analyse the phospholipid signalling responses associated with salinity stress, we performed root growth- and phospholipid analyses on plc4-KO and PLC4-OE seedlings subjected to salinity (NaCl) or osmotic (sorbitol) stress and compared these with wild type (WT). Only very minor differences between PLC4 mutants and WT were observed, which even disappeared after normalization of the data, while in soil, PLC4-OE plants were clearly more drought tolerant than WT plants, as was found earlier when overexpressing Arabidopsis PLC2, -3, -5, -7 or -9. We conclude that PLC4 plays no opposite role in salt-or osmotic stress and rather behaves like the other Arabidopsis PLCs

The profile of occupational stress in a sample of health profession academics at a historically disadvantaged university in South Africa

Background: Higher education is a high stress occupation or environment. Academics in health professions are engaged in professional training that adds clinical or profession-specific competencies to general academic and research outcomes. Academics in health professions assume many roles and must remain current in the practise of their professions that increases stress. Studies on occupational stress amongst health professions academics are lacking in the South African context.Objectives: To assess occupational stress in a sample of Health profession academics at a Historically Disadvantaged Institution (HDI).Methods: An online survey was conducted with a randomly selected sample of 51 permanent academics. The response rate was 55% after incentives and reminders. Instruments included a demographic questionnaire, Assessing emotions scale and the Sources of Work Stress Inventory. Descriptive statistics, correlation and regression were used to analyse the data. Instruments were reliable with this sample. Ethics clearance was obtained (Reg. No.: 15/4/42) and all ethics principles were upheld.Results: The sample was mostly female and the composition was consistent with the profiles of the faculty, health professions and HDIs. Small effects were reported for associations between demographics, EI and Occupational stress. Mixed results were reported for predictive relationships. EI and level of education were predictive of certain sources of occupational stress.Conclusion:  Transformations and the work environment contributed to academics experiencing occupational stress. The historical apartheid legacies still manifest in patterned ways along gender, race and professional status in the occupational stress academics experience. Health professionals constitute a legitimate subgroup that impacts the experience and management of occupational stress. EI is an important factor to consider in the experience and management of occupational stress

High Curie temperature and perpendicular magnetic anisotropy in homoepitaxial InMnAs films

We have prepared the dilute magnetic semiconductor (DMS) InMnAs with different Mn concentrations by ion implantation and pulsed laser melting. The Curie temperature of the In1-xMnxAs epilayer depends on the Mn concentration x, reaching 82 K for x=0.105. The substitution of Mn ions at the Indium sites induces a compressive strain perpendicular to the InMnAs layer and a tensile strain along the in-plane direction. This gives rise to a large perpendicular magnetic anisotropy, which is often needed for the demonstration of electrical control of magnetization and for spin-transfer-torque induced magnetization reversal.Comment: 16 pages, 5 figure

Multiple PLDs Required for High Salinity and Water Deficit Tolerance in Plants

High salinity and drought have received much attention because they severely affect crop production worldwide. Analysis and comprehension of the plant's response to excessive salt and dehydration will aid in the development of stress-tolerant crop varieties. Signal transduction lies at the basis of the response to these stresses, and numerous signaling pathways have been implicated. Here, we provide further evidence for the involvement of phospholipase D (PLD) in the plant's response to high salinity and dehydration. A tomato (Lycopersicon esculentum) α-class PLD, LePLDα1, is transcriptionally up-regulated and activated in cell suspension cultures treated with salt. Gene silencing revealed that this PLD is indeed involved in the salt-induced phosphatidic acid production, but not exclusively. Genetically modified tomato plants with reduced LePLDα1 protein levels did not reveal altered salt tolerance. In Arabidopsis (Arabidopsis thaliana), both AtPLDα1 and AtPLDδ were found to be activated in response to salt stress. Moreover, pldα1 and pldδ single and double knock-out mutants exhibited enhanced sensitivity to high salinity stress in a plate assay. Furthermore, we show that both PLDs are activated upon dehydration and the knock-out mutants are hypersensitive to hyperosmotic stress, displaying strongly reduced growth

Phospholipid Signaling Responses in Salt-Stressed Rice Leaves

Salinity is one of the major environmental factors limiting growth and productivity of rice plants. In this study, the effect of salt stress on phospholipid signaling responses in rice leaves was investigated. Leaf cuts were radiolabeled with 32P-orthophosphate and the lipids extracted and analyzed by thin-layer chromatography, autoradiography and phosphoimaging. Phospholipids were identified by co-migration of known standards. Results showed that 32Pi was rapidly incorporated into the minor lipids, phos-phatidylinositol bisphosphate (PIP2) and phosphatidic acid (PA) and, interestingly, also into the structural lipids phosphatidylethanolamine (PE) and phosphatidylglycerol (PG), which normally label relatively slowly, like phosphatidylcholine (PC) and phosphatidylinositol (PI). Only very small amounts of PIP2 were found. However, in response to salt stress (NaCl), PIP2 levels rapidly (<30 min) increased up to 4-fold, in a time- and dose-dependent manner. PA and its phosphorylated product, diacylglyc-erolpyrophosphate (DGPP), also increased upon NaCl stress, while cardiolipin (CL) levels decreased. All other phospholipid levels remained unchanged. PA signaling can be generated via the combined action of phospholipase C (PLC) and diacylglycerol kinase (DGK) or directly via phospholipase D (PLD). The latter can be measured in vivo, using a transphosphatidylation assay. Interestingly, these measurements revealed that salt stress inhibited PLD activity, indicating that the salt stress-induced PA response was not due to PLD activity. Comparison of the 32P-lipid responses in salt-tolerant and salt-sensitive cultivars revealed no significant differences. Together these results show that salt stress rapidly activates several lipid responses in rice leaves but that these responses do not explain the difference in salt tolerance between sensitive and tolerant cultivars

Extracellular spermine triggers a rapid intracellular phosphatidic acid response in arabidopsis, involving PLDδ activation and stimulating ion flux

Polyamines, such as putrescine (Put), spermidine (Spd), and spermine (Spm), are low-molecular-weight polycationic molecules found in all living organisms. Despite the fact that they have been implicated in various important developmental and adaptative processes, their mode of action is still largely unclear. Here, we report that Put, Spd, and Spm trigger a rapid increase in the signaling lipid, phosphatidic acid (PA) in Arabidopsis seedlings but also mature leaves. Using time-course and dose-response experiments, Spm was found to be the most effective; promoting PA responses at physiological (low μM) concentrations. In seedlings, the increase of PA occurred mainly in the root and partly involved the plasma membrane polyamine-uptake transporter (PUT), RMV1. Using a differential 32Pi-labeling strategy combined with transphosphatidylation assays and T-DNA insertion mutants, we found that phospholipase D (PLD), and in particular PLDδ was the main contributor of the increase in PA. Measuring non-invasive ion fluxes (MIFE) across the root plasma membrane of wild type and pldδ-mutant seedlings, revealed that the formation of PA is linked to a gradual- and transient efflux of K+. Potential mechanisms of how PLDδ and the increase of PA are involved in polyamine function is discussed

The role of interfaces and morphology on silver diffusion in hard coatings

One of the main approaches to increase the tool lifetime during dry machining of “hard-to-machine” aerospace alloys is self-lubrication by the incorporation of noble metals in hard matrixes with good mechanical and diffusion barrier properties. In this paper, the diffusion of an Ag-rich layer sandwiched between two layers of either TiN or TiSiN is studied by transmission electron microscopy and in situ Rutherford backscattering spectrometry. The layer stacks were subjected to annealing treatments at 600 ◦C and 800 ◦C for 2 hours. Three processes were found to control the diffusion of silver: the morphology of the “sandwich” layers, the formation of small voids in the involved interfaces and the sublimation of Ag in the surface at temperatures near the melting point. The study revealed that the dense TiSiN matrix allowed a significantly better control of Ag diffusion than the more open TiN matrix.info:eu-repo/semantics/publishedVersio