Hybrid Nanostructured Porous Silicon-Silver Layers for Wideband Optical Absorption

As subwavelength nanostructures are receiving increasing attention for photonic and plasmonic applications, we grew nanostructured porous silicon (n-PS) and hybrid n-PS/Ag layers onto silicon substrates and measured their reflection and absorption characteristics as functions of the wavelength, angle of incidence, and polarization state of incident light. The experimental results show that the absorption characteristics of the hybrid n-PS/Ag layer can be controlled by selecting the appropriate combination of its thickness and porosity, together with the density of infiltrant silver nanoparticles. The observed wideband optical absorption characteristics of the hybrid n-PS/Ag layers might be useful in light-harvesting devices and photodetectors, since the overall efficiency will be increased as a result of increased field-of-view for both s- and p-polarization states of incident lightR.J.M.-P. thanks Ministerio de Educación, Cultura y Deporte (Spain) for funding under grant reference number PRX17/00095. P.D.M. and A.L. thank the Charles Godfrey Binder Endowment at Penn State for continued support of their research activities. R.R. thanks the Egyptian Ministry of Higher Education, Missions section, for funding under Joint Supervision grant, call 2015–201

Uji Prestasi Mesin Pendingin Kompresi Uap yang Menggunakan Refrigeran R22 dengan Metode Pengujian Aktual dan Simulasi

Sistem pengkondisian udara yang mengatur temperatur dan kelembaban udara dalam ruangan, dalam pengoperasiannya membutuhkan refrigeran yang mudah menyerap dan melepaskan kalor. Setiap refrigerant memiliki karakteristik yang berbeda-beda yang mempengaruhi efek refrigerasi dan koefesien prestasi yang dihasilkan. R 22 adalah salah satu refrigeran yang memiliki karakteristik yang baik pada mesin pendingin. Software Genetron properties adalah sebuah software simulasi yang dapat menghitung aliran fluida atau refrigerant pada mesin pendingin. Genetron properties melakukan simulasi termodinamika untuk siklus kompresi uap dan memberikan hasil dalam bentuk tabulasi dan pada diagram Mollier diagram (h-s diagram). Pengujian prestasi mesin pendingin yang menggunakan R-22 dilakukan secara aktual dan simulasi dengan menggunakan software genetron properties. Hasil pengujian dan perhitungan menunjukkan bahwa : Kerja kompresor, COP dan performance factor pada mesin pendingin kompresi uap ketika high speed adalah 0,528 kW, 8,42 dan 0,1187; saat low speed adalah 0,528 kW; 8,52 dan 0,117. COP dari hasil pengujian dengan software genetron properties ketika high speed 2,193 saat low speed 1,415 hal ini dikarenakan mesin pendingin kompresi uap dalam keadaan tidak optima

Exploitation of nitric oxide donors to control bacterial adhesion on ready‐to‐eat vegetables and dispersal of pathogenic biofilm from polypropylene

Background Nitric oxide (NO) donors have been used to control biofilm formation. NO can be delivered in situ using organic carriers and act as a signaling molecule. Cells exposed to NO shift from biofilm to the planktonic state and are better exposed to the action of disinfectants. In this study, we investigate the capability of the NO donors molsidomine, MAHAMA NONOate, NO‐aspirin and diethylamine NONOate to act as anti‐adhesion agents on ready‐to‐eat vegetables, as well as dispersants to a number of pathogenic biofilms on plastic. Results Our results showed that 10pM molsidomine reduced the attachment of Salmonella enterica sv Typhimurium 14 028 to pea shoots and coriander leaves of about 0.5 Log(CFU/leaf) when compared with untreated control. The association of 10 pM molsidomine with 0.006% H2O2 showed a synergistic effect, obtaining a significant reduction in cell collection on the surface of the vegetable of about 1 Log(CFU/leaf). Similar results were obtained for MAHMA NONOate. We also showed that the association of diethylamine NONOate at 10 mM and 10pM with the quaternary ammonium compound diquat bromide improves the effectiveness of biofilm dispersal by 50% when compared with the donor alone. Conclusions Our findings reveal the dual role of NO compounds in biofilm control. Molsidomine, MAHMA NONOate and diethylamine NONOate are good candidates in either preventing biofilm formation or dispersing biofilm, especially when used in conjunction with disinfectants. NO compounds have the potential to be developed into tool‐kit for pro‐active practices for GAPs, HACCP and Cleaning‐in‐place (CIP) protocols in industrial settings where washing is routinely applied. This article is protected by copyright. All rights reserved

Offshore anchor piles under mooring forces: numerical modeling

A parametric study was carried out to study the behavior of offshore anchor piles under mooring forces in dense sand using a three dimensional (3-D) finite element model (FEM). The Mohr–Coulomb plastic model has been used to model the soil, and has been calibrated based on the centrifuge tests discussed in a Ph.D. thesis (published by Ramadan in 2011). The selection of model parameters and comparison of calibrated results with the centrifuge test results are discussed. In the parametric study, different pile lengths and diameters were considered to have different pile–soil rigidities. The pile was loaded at different load inclination angles to examine a wide range of loading conditions. From the current parametric study, design methods and design recommendations are given to help in improving the design of offshore anchor piles under monotonic mooring forces

Offshore anchor piles under mooring forces: Centrifuge modeling

Offshore anchor piles are seafloor moorings that keep the position of floating structures during a harsh environment. These piles are usually subjected to a wide range of monotonic and cyclic lateral-to-oblique pullout forces. Centrifuge tests were carried out to study the behavior of offshore anchor piles under mooring forces in saturated dense sand. The tests were carried out at different loading angles. All piles were jacked into the sand bed in-flight. The pile models were instrumented with strain gauges. Bending moment, soil pressure, and pile lateral deflection profiles are presented and discussed. It was found that there is a significant interaction between both tension and lateral loading. This interaction should be considered in the design of offshore anchor piles

Optimasi Parameter Permesinan Terhadap Waktu Proses Pada Pemrograman Cnc Milling Dengan Berbasis Cad/cam

The milling process is one of many machining processes for manufacturing component. The length of time in the process of milling machining is influenced by selection and design of machining parameters including cutting speed, feed rate and depth of cut. The purpose of this study to know the influence of cutting speed, feed rate and depth of cut as independent variables versus operation time at CNC milling process as dependent variables. Each independent variable consists of three level of factors; low, medium and high.Time machining process is measured from operation time simulation program, feed cut length and rapid traverse length. The results of statistically from software simulation MasterCam X Milling, then do the comparison to CNC Milling machine.  The data from experiments was statistically analyzed by ANOVA and Regression methods by software Minitab 16.Results show that the greater feed rate and depth of cut shorten the operation time of machinery, whereas cutting speed is not a significant influence. The depth of cut has the highest contribution to the value of 49.56%, followed by feed rate 43% and cutting speed 0.92%. Optimal time of machining process total is 71.92 minutes, with machining parameter on the condition cutting speed is 75360 mm/minutes, the feed rate is 800 mm/minutes and depth of cut = 1 mm. Results of comparison time machining process in software Mastercam X milling with CNC Milling machine indicates there is the difference not significant with the value of 0,35%

Rancang Bangun dan Implementasi Automatic Transfer Switch (Ats) Menggunakan Arduino Uno dan Relai

Sistem cadangan/backup catudaya mutlak diperlukan pada perangkat elektronika yang memerlukan energi listrik yang tidak terhenti. Cadangan catudaya digunakan untuk menggantikan sumber utama PLN. Pada penerapannya diperlukan sebuah perangkat pendukung berupa Automatic Transfer switch (ATS) untuk melakukan pensaklaran dari sumber utama ke cadangan catu daya atau sebaliknya. Pada paper ini, dibahas realisasi perangkat ATS berbasis mikrokontroler yang bekerja berdasarkan pembacaan arus dan tegangan. Sistem ini juga dilengkapi dengan komunikasi berbasis LAN untuk mengirim data monitoring. Setelah dilakukan pengujian, perangkat ATS dapat mengukur arus dan tegangan dengan rata-rata kesalahan 3,76% dan 0,21% pada pengukuran generator set dan sumber PLN. Pengujian lainnya, sistem relai dapat berfungsi untuk memindahkan sumber listrik dari sumber utama ke sumber cadangan atau sebaliknya

Rancang Bangun dan Implementasi Alat Ukur dan Sistem Informasi pada Listrik Satu Fasa

Sistem monitoring penggunaan listrik baik secara prabayar maupun pascabayar masih memiliki beberapa masalah, salah satu permasalahan yang terjadi adalah masih kurangnya pengawasan untuk mengetahui seberapa besar penggunaan listrik di suatu rumah atau suatu daerah. Untuk mengatasi permasalahan tersebut, diperlukan sebuah perangkat yang mampu mengukur parameter-parameter pada listrik arus AC (Alternating Current) satu fasa, dan menampilkannya hasilnya dalam suatu sistem informasi, sehingga penggunaan daya listrik dari setiap rumah atau daerah dapat diketahui jumlahnya.Dengan menggunakan papan mikrokontroler Arduino Uno sebagai pengolah datanya, parameter yang dapat diukur oleh perangkat terdiri dari arus, tegangan dan daya, data pengukuran tersebut kemudian dikirim melalui jaringan wireless ke sebuah komputer server, komputer server berfungsi sebagai penyimpanan data hasil monitoring dan mengolah data tersebut menjadi sebuah informasi yang ditampilkan dalam sebuah website.Berdasarkan hasil pengujian pada pengukuran arus didapatkan nilai kesalahan rata-rata sebesar 3,28%, kesalahan rata-rata pengukuran tegangan sebesar 0,39%, pada pengukuran nilai daya didapatkan nilai kesalahan rata-rata sebesar 8,82%. Sedangkan pada proses pengiriman data diperoleh nilai presentase error sebesar 0.1%, dan akurasi data mencapai 100%

Test Equipment Specifications Transistor

In this paper, we design a test apparatus Transistor Specification. Specification is atype of transistor is a transistor and common emitter current reinforcement value ( βDC ). The system will provide information in the form of an LED display emits greenlight when the tested types of NPN transistor and the second LED emits blue lightwhen the tested types of PNP transistors.To test the value of β, whose value is proportional to the display used by the collectorcurrent Ic