Monthly and Diurnal Variability of Rain Rate and Rain Attenuation during the Monsoon Period in Malaysia

Rain is the major source of attenuation for microwave propagation above 10 GHz. In tropical and equatorial regions where the rain intensity is higher, designing a terrestrial and earth-to-satellite microwave links is very critical and challenging at these frequencies. This paper presents the preliminary results of rain effects in a 23 GHz terrestrial point-to-point communication link 1.3km long. The experimental test bed had been set up at Skudai, Johor Bahru, Malaysia. In this area, a monsoon equatorial climate prevails and the rainfall rate can reach values well above 100mm/h with significant monthly and diurnal variability. Hence, it is necessary to implement a mitigation technique for maintaining an adequate radio link performance for the action of very heavy rain. Since we now know that the ULPC (Up Link Power Control) cannot guarantee the desired performance, a solution based on frequency band diversity is proposed in this paper. Here, a secondary radio link operating in a frequency not affected by rain (C band for instance) is placed parallel with the main link. Under no rain or light rain conditions, the secondary link carries without priority radio signals. When there is an outage of the main link due to rain, the secondary link assumes the priority traffic. The outcome of the research shows a solution for higher operating frequencies during rainy events

High-Dimensional Stochastic Design Optimization by Adaptive-Sparse Polynomial Dimensional Decomposition

This paper presents a novel adaptive-sparse polynomial dimensional decomposition (PDD) method for stochastic design optimization of complex systems. The method entails an adaptive-sparse PDD approximation of a high-dimensional stochastic response for statistical moment and reliability analyses; a novel integration of the adaptive-sparse PDD approximation and score functions for estimating the first-order design sensitivities of the statistical moments and failure probability; and standard gradient-based optimization algorithms. New analytical formulae are presented for the design sensitivities that are simultaneously determined along with the moments or the failure probability. Numerical results stemming from mathematical functions indicate that the new method provides more computationally efficient design solutions than the existing methods. Finally, stochastic shape optimization of a jet engine bracket with 79 variables was performed, demonstrating the power of the new method to tackle practical engineering problems.Comment: 18 pages, 2 figures, to appear in Sparse Grids and Applications--Stuttgart 2014, Lecture Notes in Computational Science and Engineering 109, edited by J. Garcke and D. Pfl\"{u}ger, Springer International Publishing, 201

Antimicrobial Diterpenes: Recent Development From Natural Sources

Antimicrobial resistance has been posing an alarming threat to the treatment of infectious diseases over the years. Ineffectiveness of the currently available synthetic and semisynthetic antibiotics has led the researchers to discover new molecules with potent antimicrobial activities. To overcome the emerging antimicrobial resistance, new antimicrobial compounds from natural sources might be appropriate. Secondary metabolites from natural sources could be prospective candidates in the development of new antimicrobial agents with high efficacy and less side effects. Among the natural secondary metabolites, diterpenoids are of crucial importance because of their broad spectrum of antimicrobial activity, which has put it in the center of research interest in recent years. The present work is aimed at reviewing recent literature regarding different classes of natural diterpenes and diterpenoids with significant antibacterial, antifungal, antiviral, and antiprotozoal activities along with their reported structure–activity relationships. This review has been carried out with a focus on relevant literature published in the last 5 years following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 229 diterpenoids from various sources like plants, marine species, and fungi are summarized in this systematic review, including their chemical structures, classification, and significant antimicrobial activities together with their reported mechanism of action and structure–activity relationships. The outcomes herein would provide researchers with new insights to find new credible leads and to work on their synthetic and semisynthetic derivatives to develop new antimicrobial agents

Flat Cosmology with Coupled Matter and Dark Energies

Three models of a flat universe of coupled matter and dark energies with different low-redshift parameterizations of the dark energy equation of state are considered. The dark energy is assumed to vary with time like the trace of the energy-momentum tensor of cosmic matter. In the radiation-dominated era the models reduce to standard cosmology. In the matter-dominated era they are, for modern values of the cosmological parameters, consistent with data from SNe Ia searches and with the data of Gurvits et al.(1999)for angular sizes of ultra compact radio sources. We find that the angular size-redshift tests for our models offer a higher statistical confidence than that based on SNe Ia data. A comparison of our results with a recent revised analysis of angular size-redshift legacy data is made,and the implications of our models with optimized relativistic beaming in the radio sources is discussed. In particular we find that relativistic beaming implies a Lorentz factor less than 6,in agreement with its values for powerful Active Galactic Nuclei.Comment: Version to appear in The Astronomical Journal, with a modified name- Flat Cosmology with Coupled Matter and Dark Energies. Expanded and Modified conten

The shape of equality: discourses around the Section 28 repeal in Scotland

This article focuses on conceptualizations of equality in the discourses deployed in the campaign to repeal Section 28 in Scotland. I use the parliamentary debates and two newspapers: the Daily Record, which supported the campaign to Keep the Clause, and The Guardian, which supported repeal, to exemplify the different discursive articulations around equality and citizenship. I suggest that the Scottish example provides further evidence of the ways in which liberalism naturalizes heterosexuality as the standard for citizenship and thus bequeaths a hierarchy of 'equality' and citizenship in the realm of sexuality, wherein lesbian and gay citizenship is either rendered invalid or characterized as 'special rights'. However, within the narrow confines of the parliamentary debates, more expansive and differentiated notions of citizenship and equality are evident. Whilst I conclude that the 'shape' of equality achieved through the repeal has been moulded to support institutionalized heterosexuality - with Section 28 replaced by statutory guidelines on sex education which advocate marriage - I also suggest equality is contested, both through the recognition of transformations in heterosexual family forms and the appeal to non-discrimination as a democratic principle. It is possible, therefore, that current destabilizations of the heterosexual social order simultaneously destabilize the precepts of liberal democracy

An Enhanced Zero Crossing Based HVAC Phase Synchronous Inverter for Electrostatic Generator in Microgrid Systems

Electrostatic Generator (ESG) faced far more challenges when it integrated with the phase synchronous inverter systems as ESG can generate high voltage DC and very low current. This high DC voltage needs to be converted and also low current of the ESG have to be increased for microgrid system which works generally performed by power inverter circuit. Therefore, phase synchronous inverter (PSI) is presented, to increase the inverter output current, with the aid of zero crossing voltage source controller. However, there is an issue to design the inverter which are harmonic distortion and phase angle. In this paper, a zero-crossing circuit is developed to synchronize inverter and microgrid phase and according to the simulation result, the phase angle is 3.22°. In addition, an LCL filter is designed to reduce the harmonic distortion. The performance of the PSI had been demonstrated by modeling it in MATLAB2016a software. The considered parameter of the design is input voltage 10kV, switching frequency 60Hz, modulation index 0.85 and cut-off frequency 33Hz. The simulation results show that the designed inverter can greatly improve the system stability and robustness of the microgrid system and the obtained PSI system efficiency is 97.35% that performed better compared to the related inverter techniques

IgG anti-apolipoprotein A-1 antibodies in patients with systemic lupus erythematosus are associated with disease activity and corticosteroid therapy: an observational study.

IgG anti-apolipoprotein A-1 (IgG anti-apoA-1) antibodies are present in patients with systemic lupus erythematosus (SLE) and may link inflammatory disease activity and the increased risk of developing atherosclerosis and cardiovascular disease (CVD) in these patients. We carried out a rigorous analysis of the associations between IgG anti-apoA-1 levels and disease activity, drug therapy, serology, damage, mortality and CVD events in a large British SLE cohort

Sistem Pencatatan dan Pendataan Manajemen Sumber Daya Manusia dengan Model Scrum (Studi Kasus: PT Bintang Trans Khatulistiwa)

Manajemen sumber daya manusia atau biasa disebut Human Resource Development (HRD) merupakan salah satu bagian terpenting dalam suatu Perusahan atau organisasi. Karena, fokus utama manajemen sumber daya manusia adalah memberikan kontribusi bagi sukses atau tidaknya suatu organisai atau Perusahaan. Tugas dan kegiatan HRD dalam suatu Perusahaan adalah menangani permasalahan-permasalahan yang berkenaan dengan pengelolaan sumber daya manusia pada sebuah organisasi (Perusahaan). Pengelolaan data sumber daya manusia pada PT. Bintang Trans Khatulistiwa (BTK) masih bersifat manual, sehingga Perusahaan kesulitan dalam memperoleh informasi yang berhubungan dengan sumber daya manusia secara cepat dan akurat. Untuk menangani permasalahan tersebut, maka kami mengusulkan pembuatan suatu sistem informasi manajemen Sumber Daya Manusia yaitu Aplikasi Sistem Pencatatan dan Pendataan Manajemen Sumber daya Manusia yang nantinya dapat membantu bagian HRD untuk menjalankan tugasnya, mulai dari proses pendataan karyawan, pendataan absensi, pengajuan cuti, proses payroll atau penggajian dan penilaian karyawan hingga pembuatan laporan, serta dapat menghasilkan informasi yang dapat digunakan untuk pengambilan keputusan bagi seorang manajer. Dalam pengembangan sistem ini menggunakan pendekatan metode Scrum dan menggunakan metode cause effect diagram (fishbone) sebagai dasar untuk melakukan analisa permasalahan, sehingga nantinya akan didapatkan solusi-solusi untuk pembuatan sistem pada penelitian ini.Keywords— Sistem informasi, sumber daya manusia, Scrum, Fishbon

Penggunaan Zeolit Alam Sebagai Katalis Dalam Pembuatan Biodiesel

Biodiesel merupakan energi alternatif yang dapat menggantikan bahan bakar diesel. Biodiesel telahdibuat melalui reaksi transestrifikasi minyak goreng bekas dengan bantuan katalis. Penggunaan zeolitalam sebagai katalis dapat memudahkan separasi biodiesel dari produk samping (gliserol). Pembuatanbiodiesel dilakukan pada suhu 60oC, perbandingan minyak dan metanol 4:1 (volum) denganmemvariasikan waktu reaksi dan konsentrasi katalis zeolit. Hasil penelitian menunjukan bahwa waktureaksi 5 jam dan konsentrasi katalis zeolit 1% memberikan yield biodiesel terbesar yaitu 12%