Power factor and your electrical utility bill in Egypt

This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. Copyright @ 2003 IEEEBeside being a good neighbor and not causing harmonic voltage for others that are connected to your electrical distribution circuit, complying with the legal requirements of IEEE standards 519, and maintaining safe and economical operating environments for electrical equipment within your physical load, there is another very good reason to maintain a good power factor: saving money on your electrical utility bill. Utilities often encourage consumers to maintain a high PF by applying tariff clauses, which penalize consumers for low PF. This letter discusses the topic

Practical considerations regarding power factor for nonlinear loads

This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. Copyright @ 2004 IEEEThe choice of LC compensator may be constrained by the availability of manufacturers units. To account for this, the capacitor values are chosen from among standard values and for each value the transmission losses is minimized, or power factor is maximized, or transmission efficiency is maximized. The global minimum or maximum is obtained by scanning all local minims or maxims. The performance of the obtained compensator is discussed by means of numerical examples

Polysaccharide Ecocomposite Materials: Materials: Synthesis, Characterization and Application for Removal of Pollutants and Bacteria

A novel, simple and totally recyclable method has been developed for the synthesis of nontoxic, biocompatible and biodegradable composite materials from cellulose and chitosan. In this method, [BMIm+Cl-], an ionic liquid (IL), was used as a solvent to dissolve and synthesize the [CEL+CS] composite materials. Since the IL can be removed from the materials by washing them with water, and recovered from the washed solution, the method is totally recyclable. XRD, FTIR, NIR and SEM were used to characterize the materials and to confirm that CEL and CS were successfully regenerated by the method without any chemical transformation. More importantly, we have successfully demonstrated that [CEL+CS] material can serve as an effective adsorbent for removal of various endocrine disruptors including polychlorophenols and bisphenol A. This is because the composites have combined advantages of their components, namely superior chemical stability and mechanical stability (from CEL) and excellent adsorption capability for pollutants (from CS)

LC compensators for power factor correction of nonlinear loads

This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. Copyright @ 2004 IEEEA method is presented for finding the optimum fixed LC compensator for power factor correction of nonlinear loads where both source voltage and load current harmonics are present. The LC combination is selected because pure capacitive capacitors alone would not sufficiently correct the power factor. Optimization minimizes the transmission loss, maximizes the power factor, and maximizes the efficiency. The performance of the obtained compensator is discussed by means of numerical examples

ANALISIS TEKSTUR PARKET KAYU JATI DENGAN MENGGUNAKAN METODE STATISTIKAL GRAY LEVEL DIFFERENCE METHOD

Dalam industri kayu sekarang, jati dijadikan keping-keping parket (parquet) penutup lantai. Akibat krisis ekonomi global kegiatan usaha ekspor produk flooring parket yang dibuat dari bahan baku kayu jati mengalami penurunan drastis. Oleh karena itu standar mutu dari produksi kayu jati parket harus terus ditingkatkan. Kebutuhan perusahaan manufaktur yang tinggi untuk menjaga kualitas produk yang lengkap, memerlukan kontrol selama produksi dan pada akhir proses. Selama ini kontrol yang digunakan adalah kontrol manusia yang tidak sepenuhnya dapat diandalkan dan tidak menjamin kualitas dari total kontrol. Hal ini dapat diatasi dengan menggunakan komputer visi sebagai inspeksi visual produk control. Dalam menentukan klasifikasi otomatisasi maka harus ditentukan variabel yang akan digunakan dengan analisa tekstur. Analisis tekstur jenis kayu jati parket bertujuan menentukan variabel untuk mengenali parket ke dalam beberapa jenis parket yang berbeda- beda tapi mempunyai sifat yang serupa ke dalam kelompok-kelompok berdasarkan pemakaiannya. Dalam penelitian parket dianalisa dengan menggunakan metode statistikal grey level difference method (GLDM). Nilai features yang digunakan dalam analisa tekstur ini adalah Contrast, Angular Second Moment (ASM), Entropy, Inverse Difference Moment (IDM), dan Mean. Data dalam penganalisasian terdiri dari 13 data citra kayu jati parket yang akan dianalisa untuk dijadikan prediksi klasifikasi ke dalam jenis kayu jati parket A,B, atau

Arthroscopic dorsal wrist ganglion excision with color-aided visualization of the stalk: minimum 1-year follow-up

Background Dorsal wrist ganglia (DWG) are a common, benign soft-tissue mass of the wrist. Excision of DWG is a common procedure performed by hand surgeons and may be performed using either open or arthroscopic techniques. This study aims to evaluate the frequency of stalk visualization with intralesional injection of inert dye in the course of arthroscopic excision along with incidence of recurrence with a minimum of 1-year follow-up. Methods Upon IRB approval, a retrospective chart review was performed identifying 27 patients who had consecutively undergone arthroscopic excision of a DWG with the color-aided technique at our institution with a minimum follow-up duration of 12 months. Intraoperative findings were reviewed. Patients were contacted to investigate for incidence of recurrence. Results Of the 27-patient cohort, the ganglion stalk was identified in 100 % of the color-aided arthroscopic DWG excisions. Ganglion recurrence was identified in one patient, an incidence of 3.7 %. Conclusions The color-aided technique for arthroscopic DWG visualization was found to be a safe and valuable tool for surgeons performing arthroscopic DWG resection. The intraarticular ganglion stalk was identified in 100 % of cases and patients responded well with a low incidence of recurrence

Effect of connecting shunt capacitor on nonlinear load terminals

This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. Copyright @ 2003 IEEEThe use of terminal shunt capacitance has different effects on the displacement factor and distortion factor components of the power factor. These effects are considered for nonlinear loads with ideal supply, and also where the supply impedance exists but is small compared with the load impedance. Optimization of the displacement factor is found to result in reduction of the distortion factor to a minimum value

METADATA PADA FILE GRAFIK SEBAGAI REFERENSI UNTUK MENGHINDARI KESALAHAN INPUT

Database merupakan suatu tempat untuk menyimpan data yang saling berhubungan. Data yang tersimpan dalam database dapat berupa angka, karakter, maupun gabungan keduanya. Kebutuhan menyimpan data grafik dalam database grafik kini semakin kompleks, indikasi ini terlihat dari seringnya terjadi kesalahan dalam operasi pencocokan pada database .Dalam paper ini, kami menyarankan untuk memasukkan metadata pada suatu data grafik tanpa merusak file grafik tersebut yang nanti akan dicocokkan dengan database grafiknya. Kemudian metadata tersebut diekstrak kembali untuk mendapatkan metadata awalnya, sehingga dapat dilakukan perbandingan antara metadata pada properti yang bersesuaian dengan properti database grafik .Contoh sederhana adalah data image rontgen memiliki ID pasien, nama, dan tanggal lahir. Untuk mengecek metadata dengan field nama, kami menggunakan metode pencocokan string dengan algoritma hash. Dan untuk pengecekan tanggal lahir kami membuat standarisasi format tanggal yang digunakan dalam database. Apabila terjadi ketidakcocokan maka akan terdapat beberapa error level, jika error level semakin kecil maka metadata semakin mendekati data sebenarnya dan sebaliknya. Untuk contoh kasus ini, kami membuat tiga tingkatan kesalahan dalam error level. Kontribusi dari pendektan teknik di atas dapat dimanfaatkan secara langsung untuk grafik database dan keamanan sistem data gambar yang sensitif agar terhindar dari kesalahan penginputan data gambar yang tepat

Reversible optical doping of graphene

The ultimate surface exposure provided by graphene monolayer makes it the ideal sensor platform but also exposes its intrinsic properties to any environmental perturbations. In this work, we demonstrate that the charge carrier density of graphene exfoliated on a SiO$_2$/Si substrate can be finely and reversibly tuned between electron and hole doping with visible photons. This photo-induced doping happens under moderate laser power conditions but is significantly affected by the substrate cleaning method. In particular, it is found to require hydrophilic substrates and to vanish in suspended graphene. These findings suggest that optically gated graphene devices operating with a sub-second time scale can be envisioned but also that Raman spectroscopy is not always as non-invasive as generally assumed