A study of the effect of palm oil as MQL lubricant on high speed drilling of titanium alloys

The main objective was to study the potency of MQL palm oil (MQLPO) as a lubricant in the high speed drilling of Ti–6Al–4V. For the comparison, MQL synthetic ester (MQLSE), air blow and flood conditions were selected. Uniform flank wear, micro-chipping, thermal cracking and flaking were the dominant tool failure modes. It was found that MQLSE and MQLPO gave comparable performance with the flood conditions. In addition, MQLPO outperformed MQLSE on the cutting forces, temperature, power and specific cutting energy. This shows that palm oil can be used as a viable alternative to synthetic ester for MQL lubricant

Single-, Dual- and Triple-band Frequency Reconfigurable Antenna

The paper presents a frequency reconfigurable slot dipole antenna. The antenna is capable of being switched between single-band, dual-band or triple-band operation. The antenna incorporates three pairs of pin-diodes which are located within the dipole arms. The antenna was designed to operate at 2.4 GHz, 3.5 GHz and 5.2 GHz using the aid of CST Microwave Studio. The average measured gains are 1.54, 2.92 and 1.89 dBi for low, mid and high band respectively. A prototype was then constructed in order to verify the performance of the device. A good level of agreement was observed between simulation and measurement

Kajian Kualitas Pelayanan Tera Ulang Meter Taksi Pada Unit Pelaksana Teknis Dinas Metrologi Dinas Perindustrian Dan Perdagangan Provinsi Sulawesi Utara

The aim of this study is to determine and describe the quality of service of taxi meter re-calibration in Metrology technical service unit North Sulawesi Province. So far, there is no success parameters that can be used as a reference service that the service has been provided by either or even vice-versa. Method used in this study was a qualitative method using a qualitative descriptive approach. The data was collected by observation, interviews and documentation obtained from the informants in this study, namely the five informants as a taxi driver and data was synchronized with the chief executive office of metrology unit, taxi manager, and executive officers re- calibration. Results and discussion showed total of armada taxi meter re- calibration in UPTD Metrologi as much as 315 unist. Total re-calibration in 2011 that qualified for the test on re-calibration statue valid and legal based UU No. 2 tahun 1981 about metrologi legal as much as 268 units, and not qualified as much as 47 units, among 20 armadas deviate from the technical provision, ie mileage shown over allowed toleranted is 4 % of mileage that had been tested so that could harm the consumen taxi users. 17 armadas damaged and in garage. Conclusions in this research is taxi meter company that operating in North Sulawesi Province not obey yet the rule that on law\u27s requirement except the Blue Bird company as national company that had been applied trade and nexus law. Otherwise the company not applied a tight rules against taxi meter USAge so that transaction the drivers between the pasengers use agreement (mouth argo). There are unformity tariff between one company and the other company. So that make the consumen taxi services users confused. This case not justified on UU No. 2 tahun 1981 about Metrology legal

Optimum transmitter receiver ratio for maximum wireless energy transfer

Due to high demand of using cordless mobile device, the interest in wireless energy transfer (WET) has been growth intensively. This paper presented a method to obtained optimum transmitter receiver ratio for maximum performance of WET system using different initial antenna size at various distance. An optimized algorithm has been developed to determine the optimum ratios that yield the highest wireless transfer efficiency (WTE) at near field communication (NFC) frequency, 13.56MHz. 30mm × 30mm single square loop antenna is used as initial size of both transmitter and receiver using FR4 with operating distance = 50mm. Operating distance and initial size of the antenna will be varied and the effect to the WTE will be studied using Matlab, verified using Microsoft Studio CST. At distance = 50mm and initial size of the antenna = 30mm × 30mm, optimum transmitter to receiver ratio equal to 1:3 is obtained. The pattern of optimum transmitter receiver ratio between Matlab and CST has met an agreement. This research limited to integer transmitter receiver ratio used only and no decimal number being involved in magnify the transmitter size

Multiband monopole antenna for mobile applications

— In this paper, a multiband monopole antenna has been proposed for mobile applications. The monopole antenna has simple structure with a physical size of 15 cm × 7 cm. The antenna consists of monopole shape loaded by a set of folded arms with a varying length which lead to a better impedance matching result and multiband performance. The simulated results show that the proposed antenna provide multiband frequency operation of 0.8 GHz, 1.8 GHz 2.1 GHz, 2.6 GHz and 3.5 GHz which covers the range from 0 to 4 GHz. The antenna is designed to operate at sub-6 GHz which proposed as lower frequency band to deliver 5G in early stage. The designed antenna has been fabricated and measured to validate the simulated results. RF Coaxial U.FL Connector was used as the port connector. The measurement results agrees well with the simulated ones for all frequency bands

An Electronically Reconfigurable Patch Antenna Design for Polarization Diversity with Fixed Resonant Frequency

In this paper, an electronically polarization reconfigurable circular patch antenna with fixed resonant frequency operating at Wireless Local Area Network (WLAN) frequency band (2.4-2.48 GHz) is presented. The structure of the proposed design consists of a circular patch as a radiating element fed by coaxial probe, cooperated with four equal-length slits etched on the edge along x-axis and y-axis. A total of four switches was used and embedded across the slits at specific locations, thus controlled the length of the slits. By activating and deactivating the switches (ON and OFF) across the slits, the current on the patch is changed, thus modifying the electric field and polarization of the antenna. Consequently, the polarization excited by the proposed antenna can be switched into three types, either linear polarization, left-hand circular polarization or right-hand circular polarization. This paper proposes a simple approach that able to switch the polarizations and excited at the same operating frequency. Simulated and measured results of ideal case (using copper strip switches) and real case (using PIN diode switches) are compared and presented to demonstrate the performance of the antenna

Inovasi dan retensi dalam dialek Hulu Tembeling

Inovasi dan retensi adalah dua konsep penting dalam linguistik perbandingan sejarawi. Inovasi merujuk kepada perubahan sesuatu ciri bahasa purba dalam bahasa atau dialek semasa; manakala, retensi pula adalah pengekalan sesuatu ciri bahasa purba dalam bahasa atau dialek semasa. Bertolak daripada kedua-dua konsep tersebut, makalah ini membincangkan ciri inovasi dan retensi yang wujud dalam dialek Hulu Tembeling (DHT). Secara khususnya makalah ini hanya membicangkan satu ciri inovasi dan retensi dalam DHT iaitu perubahan segmen bunyi yang terjadi pada konsonan nasal akhir dan pengekalan vokal tinggi pada posisi suku kata praakhir. Harus dinyatakan bahawa penentuan sama ada sesuatu ciri itu dapat dikategorikan sebagai inovasi atau retensi adalah melalui pendekatan perbandingan yang lazim dalam linguistik perbandingan sejarawi. Sehubungan itu, data-data dialek Hulu Tembeling akan dibandingkan dengan bahasa Malayik Purba (MP) yang telah direkonstruksi oleh Adelaar (1992). Pewajaran perbandingan sebegini adalah kerapatan hubungan bahasa purba tersebut dengan DHT. Pendekatan perbandingan yang dijadikan alat analisis didasarkan pada hipotesis kajian ini iaitu segmen bunyi yang menunjukkan perbezaan dengan MP dikategorikan sebagai inovasi; sebaliknya, segmen yang direfleks secara linear dikategorikan sebagai retensi. Ciri inovasi dan retensi ini selanjutnya dihubungkan dengan beberapa faktor yang relevan untuk dikaitkan sebagai penyebab kewujudannya iaitu pengelompokan dialek Hulu Tembeling, ketidakstabilan dialek tersebut ekoran perubahan ciri linguistik yang sedang berlangsung dan kewujudan rantai dialek di Lembangan Sungai Pahang

The hymenopterous pollinators of Himalayan foot hills of Pakistan (distributional diversity)

Studies were undertaken to explore the diversity of hymenopterans pollinators from a diverse agroecosystems of Himalayan foot hills comprising the orchards of pome and stone fruits at different altitudes from 2200 to 3000 m from sea level. Field experiments were conducted on seven commercial fruit orchards at five various localities. Out of the total 448 specimens, 60.94% were found in an antemeridian (A.M.) phase and 39.06% specimens were found in post-meridian (P.M.) indicating their activity both diurnal and crepuscular. Rank abundance values revealed that 9 species in 5 genera belonged to four families of order Hymenoptera comprising the diversity of Osmia cornifrons Panzer, Anthophora niveo-cincta (Smith), Anthophora himalayensis Rad., Anthophora crocea Bangham, Bombus tunicatus (Smith), Xylocopa dissimilis Lepel., Xylocopa rufescens Smith, Andrena harrietae Bangham and Andrena anonyma Cam. The calculated values of all diversity indices showed that the lowest diversity was found in a monoculture fruit habitat with well weeded orchards, whereas the diversity of pollinators was found greater in multiple cultures with partially weeded orchards particularly during the successional stage of full bloom in both pomes and stone fruits. A significant difference in the pollinators’ population was seen in the orchards with undisturbed surroundings. The natural ecosystem offers more opportunities of refuges for the insect pollinators compare to those orchards with clean cultivation.Key words: Diversity, agro-ecosystem, fruit orchards, hymenopterans pollinators, monoculture

Single channel magnetic induction spectroscopy technique for fetal acidosis detection

Current fetal acidosis diagnosis needs an invasive measurement which required a doctor to puncture fetal scalp to acquire blood pH. This method introduced risk to the fetal which fetal scalp may bruise and infected. This paper discusses a noninvasive method employing a single channel magnetic induction spectroscopy technique as an alternative method to diagnose acidosis in fetal without puncturing the fetal scalp. The studies are based on numerical simulation models to investigate the most feasible sensor coil that is sensitive and effective to be implemented in hardware setup as the shape of coil influences directly the sensing performance of the magnetic induction spectroscopy system. The study has found that the circular coil is more sensitive than linear coil. The system tested with different pH samples to mimic the blood pH value. The result is very promising with good correlation approaching 1 has been achieved. Therefore, magnetic induction spectroscopy technique has good opportunity to be applied as an alternative method to detect acidosis in the fetal with circular coil is performed as the best sensing coils for MIS hardware